Tuesday, 1 September 2015

Written vs Verbal


Communication of technical information between software developers is crucial. The debate about the advantages and disadvantages of written vs verbal communication has been going on for at least half a century, but even half that time ago, thorough written documentation was generally considered essential. For example, the SEI (Software Engineering Institute) released the CMM (Capability Maturity Model) around 1990 which heavily emphasized documentation of the product (as well as the procedures used to create the product).

Quality Standards        

I did a post-graduate diploma in SQA at UTS in 1993. Much of the software quality stuff was really useful (and found its way into Agile).

However, I found CMM and quality standards (like ISO 9001, etc) not that useful if not downright burdensome. They seem to me like a money-making scheme for certification organizations and consultants.
The debate usually centers around requirement specifications or specs. I have talked about the problems of writing detailed up-front specs before so I won't go into that again (see Agile Design). [However, in brief specs are incorrect, incomplete, inconsistent, out of date and just generally difficult to understand and use - this is almost inevitable, no matter how hard you try to get them right and maintain them.]

Agile reopened this debate. One of the five core principles of the Agile Manifesto is to Favor working code over documentation. This is taken by many people to mean that Agile has no place for written documentation. This is not true - Agile does not try to do away with documentation when it is demonstrably useful to the developers and it cannot be replaced with more effective alternatives. (There are often better alternatives, usually in the form of code, of which my favorite is Unit Tests).

Written vs Verbal

We will start with a recap of what I believe is common knowledge.

Written documentation is good for well-understood information that needs to be disseminated to different people, and/or at different times. Moreover, the readers (and the writers) can go at their own pace. Another advantage is that the author(s) have the opportunity to fix and refine the document and others can validate it.

* The problem of misunderstanding written words has resulted in many problems due to hastily written emails. Often something written as a joke is taken seriously.

This is the reason that emoticons (like :) were invented, and why you should carefully read emails, and think about how they may be interpreted, before sending.
Verbal communication is good where the actual subject matter is less well-defined or understood, and/or there is a need for interaction between the participants. A commonly cited advantage is that there is often less misunderstanding due to secondary information being conveyed beyond the actual words spoken* - intonation, body language etc.

On the other hand, studies show that verbal communication is much less likely to be remembered. Further, many work environments have other effects that can interfere with verbal communication such as different accents, background noise, and simply the emotions and distractions of interpersonal communication.

Apart from these well-known attributes, here are a few more points from my own observations.
  1. In my experience some people are good at learning verbally, but many are not. The best approach depends on the team and should allow for personal preferences and abilities. If you favor one approach or the other you may drive away good people.
  2. In a top-down, autocratic environment people are scared to make a mistake. Verbal communication does not work well since someone will not ask for clarification for fear of appearing stupid. They may also not want to repeatedly ask for clarification for fear of embarrassing the explainer.
  3. In the software industry (at least in my experience) there are professionals from many different backgrounds. Verbal communication can be problematic when people of different NESBs (non-English speaking backgrounds) attempt to communicate. Written communication can often avoid this problem.
  4. Written documentation is often used more for self-protection than in any valid attempt to communicate information. (See the case study below.)
  5. Finally, and possibly most importantly, the documentation produced by a team is typically written by one (or perhaps two or three) people. Other team members have no ownership, and are disinclined to modify or even use the documentation.

Document Types

We talked briefly about "specs" above but we should clarify the different types of documents typically required for a software project. Traditionally, there are three main documents. (There may also be ancillary documents, such as project plans, test plans, etc.) I will later describe how these documents are used (or avoided) in an Agile environment.
  1. User Manual - how to use the software
  2. Specifications - what the software does
  3. Design Document - how it does it
There are variations and combinations of the above but these are the three essentials. Note that I won't talk about the User Manual (as this discussion is limited to technical documentation) except to say that one variation is to use the User Manual in place of the specs - that is, first write a detailed User Manual and use that to specify what the software is to do. (In my opinion, this is just as bad an idea as writing detailed up-front specs - I just mention it for completeness.)

Technical Documents

In CMM jargon:
specs == "Software Specifications"
design == "Technical Specification"
The "technical" documents are the specs and the design. You may know them by other names. For example, the specs are sometimes called the functional specification, customer requirements, etc. What I call the design document may be called the internal design, software architecture, technical design document, etc. Traditionally an analyst writes the former and a designer creates the latter - but these are often done by the same person (analyst/designer).

Sometimes these two technical documents are also combined, perhaps intentionally, but more often because the analyst/designer has already formed an opinion of how the software will work internally. The specs become full of implementation details, which can needlessly restrict design choices.

Additional problems arise because technical documents try to serve different purposes. Ostensibly they are to tell the developers what to do, but in practice their main audience is the client. First, they they must be comprehensive and sound authoritative to give the client confidence that the project is on the right track. Another purpose is to protect their writers. (You can tell this sort of document by the large number of exclusions, restrictions, provisos, assumptions, and client responsibilities -- for the writer(s) to later point to, when the client is unhappy -- and by the fact that they have to be "signed off" by a large list of stakeholders.)


I was attempting to wean the team off detailed written specifications. It was assumed that the client required detailed specs but we found the client was quite happy to work closely with us to create user stories each accompanied by a few acceptance criteria. This was a revelation and even a relief to most of the developers but I still had one experienced developer who was vehemently opposed. After some discussion I discovered why. Here is his story...

My colleague had worked for over a year on a large project which was finally delivered. Apparently, this was not a typical waterfall project but the contract did require a large detailed specification to be signed off by all relevant stakeholders. After almost two years the product was delivered but the client was unhappy. There was a large gap in the design. They argued that it was a major oversight that should have been avoided or at least discovered much earlier. My colleague was the scape-goat for the problem, being responsible for much of the analysis and design. After scrutinizing the design document he was saved by one small sentence which implied that the "gap" was explicitly not covered. Since the client had signed off on the document they were clearly the ones at fault. One small sentence in the specifications (not even written by him) saved my colleague his job!

Design Document

In previous posts I talked extensively about the problems with big up-front specs (see the section called Problems of BDUF in Agile Design). A different problem is that the design document is typically underdone. (This happens even, or especially, in an Agile environment as I discuss later.)

Most of the projects I have worked on in the last three decades had absolutely no design documents. Some possible reasons were:
  • it simply didn't occur to anyone to document the design 
  • the specs already included much of the design 
  • the developers created the design on the fly and never got around to documenting it 
  • the developers simply found it too hard to put technical details into words 
  • there was nobody willing and/or able to write the document 
  • the developers thought the implemented design was "self-describing" 
  • there was unwillingness to document something that was likely to change 
  • there was unwillingness to write something that would be criticized or simply ignored 
  • management didn't ask for it 
I have had the good fortune to work with some excellent teams that did document the system architecture. However, even then the document was generally ignored or under-utilized. Reasons for this sort of problem might be that developers:
  • don't know the document exists 
  • can't understand the document 
  • have no incentive to understand it 
  • think it is incorrect (even when it isn't) 
  • believe it is out of date, especially as the original author(s) have left 
  • feel no ownership and so will not update or even read it 


Many Agile proponents take the approach that technical documents should be just sufficient and no more -- I call this MVD (minimum viable documentation). The problem with MVD is you can get away with providing no design document whatsoever, unless there are contractual requirements. MVD is short-sighted as it creates huge maintenance problems down the track, especially once the original developers have left.

So how should you approach documents in Agile? I will look at it from three different angles: who, when, and what. The nice thing is that all ways of looking at the problem lead to similar conclusions.


First you need a clear idea of who a document is written for. Technical documents (especially those that need to be "signed off") have more than one audience which muddies their purpose. A simple example is that have a lot of detail (superfluous for developers) intended to ensure testers consider all scenarios.

However, the main problem with specs is they are primarily intended to make the customer happy. First, the specs must be detailed to give the client confidence that the developers know what they are doing.

“for the developers,
by the developers”
Just as important though is who is the document written by. A document is not fully utilized unless the users of the document feel they have ownership of it. (It also makes it much more likely it will be kept up to date.) For the team to have ownership the team needs to write the document. Not just one or two people but all the developers need to contribute.

In summary, you need to be clear on the document's audience and purpose. Technical documents need to be written for the developers, by the developers.


The problem can alternatively be seen as one of timing. As we saw above, the purpose of many documents is mainly to demonstrate to the customer that the team know what they (the customer) wants and know how to give it to them. Hence the document is detailed but all this detail is provided much too early which invariably locks the project into a design, which is invariably not the best design.

In large waterfall projects mountains of documents were often written in the analysis and design phases even before the programmers had joined the project!

On the other hand real world projects before Agile were typically not done anything like that. Developers had to (and sometimes even wanted to) produce documentation but to avoid having to continually modify it to match the changing design (or have it become out of sync) most teams left writing design documents till the end of the project. Unfortunately this is the time when the team probably has little time and motivation to write it, or those who started to write it had left, etc.

The Agile approach is one of JIT-design. Design is not done until needed. This is the Goldilocks time to update the documentation - not too early and not too late but just in time.

I will note here that this is another classic case of DIRE. The developers should be documenting the design as they build it. Of course, this does not mean updating the document whenever any aspect of the design changes. The code itself is the "true" documentation, but looking at the code is not useful for getting a high-level overview. As I have mentioned many times before Unit Tests are very useful for documenting the behavior of modules and how interfaces are meant to work (see the section on Documentation in Unit Tests). However, at the highest level it is important to update design documentation that reflects major changes, particularly if they are core and not likely to change in the future.


So what does Agile documentation contain?

It should always record the current state of the system, not some past state or a future proposal. As I mentioned above, it is owned by the team and updated with the code. The documentation is focused on the customer, as it reflects system changes that are driven by the backlog.

What does it not contain?

You can tell a document is not "Agile" when it is used to tell people what to do. For example, the traditional specification is written by the analysts/designer to tell the programmers what they are to do. Another clue is that it contains lots of disclaimers and provisos and its main purpose is to gain the client's approval.

The author of this type of document is focused on the document itself (and how it is perceived) rather than the success of the product. In other words, it has to be nicely formatted according to company standards, appear complete and authoritative and signed off by all stakeholders.


As a bonus I will give an example of how a design document may be created for an Agile project.
  1. Initially, the developers gather a few user stories and create a simple first version of the software. There is no design documentation as it is easy enough to understand it by inspecting the code. The team have yet to decouple any parts of the system since it is not yet clear why or how to do so.
  2. As the system grows it becomes obvious how to (but more importantly necessary to) divide the system into modules. How these modules work is "documented" using a comprehensive set of Unit Tests, not written documentation. However, the team needs to create a brief design document that explains the overall design, in particular why it was necessary to decouple certain areas.
  3. As the system grows many more modules will be needed. New modules will be added or existing ones split as the need arises. The design document is updated by the team as the actual code is updated. This sort of documentation is invaluable for new people joining the team and even for existing team members as the design becomes more complex.

Finally, I should explain the vital role of code in the documentation debate. As the saying goes the best information comes "straight from the horses mouth". In software development the actual operational software is the "horses mouth". To extend the, admittedly poor, analogy Unit Tests might then be the "jockey"; Unit tests are also code which interfaces directly with the "horse".

More traditional documentation is getting further from the horses mouth. In fact most that I have encountered is akin to an ill-informed tip overheard at the local pub.

Getting back to the point. You often don't need written documentation since the actual behavior of the software is a better form "documentation". Further, Unit Tests demonstrate how modules can be used, are often easier to understand (and can even be stepped through in the debugger), are typically more comprehensive (especially with regard to error-handling) and are never out of date (if run regularly).


An objection I often get: "I think the software is doing the wrong thing. How can I check if there is no written document describing what it should do?" My reply is: "What do you think it should do? And more importantly, what does the customer think it should do?"

However, sometimes the customer doesn't care and the behavior is determined by external reasons, such a technical limitations, government regulations, etc. Sometimes UAT (user acceptance test) scripts can document the correct behavior - but UAT scripts have a habit of quickly becoming out of date.

In many cases this is a valid objection and a good example of why documents are still required.


In the past, waterfall methodologies, quality standards (particularly CMM), and simply the influence of how things are done in other "engineering disciplines" have meant that there is far too much emphasis on documentation in the software development process. On the other hand Agile extremists have gone to the other extreme of MVD or even no documentation. The right balance is somewhere in between.

That said, it's better to err on the side of too little. But I still believe that for a large project some documentation is needed to explain or remember important details that cannot be easily gleaned from the code.

Some simple rules to remember are:
  • avoid documentation if you can
  • there are often better alternatives (like Unit Tests)
  • technical documentation is written for the developers only
  • practice continuous documentation - ie, update the doc at the same time as the code
  • ownership of documents by the team is just as important as content

Saturday, 18 April 2015

Team Collaboration

Collaboration is at the core of problems experienced when implementing Scrum (or any team work). As I mentioned last week, consideration of personalities is important when composing a team. This is a big/important enough subject that I decided to devote a whole post to it.

Developers, generally, are simply not good at working in a team. In the past, good programmers could get away with working fairly independently in their own specialized area. Nowadays, larger projects, more varied project types and different development methodologies means that good team-work is expected of everyone. It is a simple demonstrable fact that collaborative (Agile) teams invariably produce a better outcome, more efficiently and with less risks.

“collaborative teams
invariably produce
a better outcome...”
You can try to hire people with the right personality, but it's not necessary (and sometimes you simply don't have that choice). Luckily, using Scrum and some tips that I mention below, most developers can learn to work as part of a team, and even enjoy working with others for a worthwhile goal.

Why Teams Don't Collaborate

Poor collaboration is most obviously seen in conflict over technical issues. In three decades in the industry I have seen this many times. When you get to the heart of the matter the problem is rarely purely a technical issue but also due to personality conflict, poor communication or interpersonal skills (or even emotional disturbance).

Differences of opinion on technical topics such as software design, coding standards, etc are inevitable. Often this is simply a sign that different people have different priorities - eg, different team members may focus on different aspects of the quality of the code such as efficiency vs maintainability. (See Importance of Developer Quality Attributes for more on software quality attributes and their relative importance.) When the team is collaborating, and pulling in the same direction these issues can disappear, or become much easier to resolve, since team members are more amenable to compromise.

Managers often realize there is more behind the disagreement, such as a clash of egos. But they fail, or are reluctant to, to dig deep enough to find that some of the team may feel disempowered, threatened or generally dissatisfied. Again, a Scrum team overcomes these sorts of problems by empowering and encouraging communication and collaboration.


Typical Developer DISC Profile
To get an idea of why collaboration does not happen let's look at the personality of a typical developer. Last month I mentioned the DISC system of personality assessment (see Team Composition). Developers tend to fall in the S-C-D range and are predominantly of the C personality type (see diagram at right). This means they are conscientious and competent, striving for accuracy and quality. However, they prefer to work independently with little social interaction.

It seems that the software industry tends to attract people who are averse to collaboration. (In fact DISC assessors recommend software development as an appropriate career for those with a C personality type!) This is the major problem when attempting to get a Scrum team to collaborate and self-organize.

So do we give all new recruits a personality test and only hire developers with the right personality type? No -- that's not a good idea. It would greatly reduce the pool of potential candidates, some of whom may be otherwise ideally suited to the role. The fact is almost all developers (even the extreme case of someone with Aspergers) can learn to collaborate, and even enjoy working in a small self-organizing team.
My Internal DISC Profile

I believe this non-collaborative behavior is primarily a conditioned or learnt response, as I explain later. This is clearly shown with DISC personality assessments of a typical developer. DISC assessments give two personality profiles - called internal and external. An internal profile (see diagram at right) reveals a person's natural tendencies, whereas the external profile (see diagram below) shows actual behavior in the work environment. In disempowering environments developers typically suppress their collaborative tendencies.

My External DISC Profile
For example, last year I had a DISC assessment which showed that for my Natural/Internal personality my S and C styles were about average. However, for my Adapted/External personality my S style had disappeared. (The S personality type is supportive and likes working closely with other people.)

What was it that suppressed my natural collaborative tendencies? I think there are a number of factors which I cover in the next few sections. Further, I also believe that proclivity to working in a small team is a part of human nature as I explain later in the section below entitled Homo Habilis.


Training in the industry tends to reinforce the notion that software development (at least design and coding) is a solitary activity. For example, in all the courses I did at uni. just one (of the dozens) of modules I took involved working as part of a team - my 3rd year course on "Software Engineering". Things have undoubtedly improved since 1983 but I still believe there is a problem.


Even more significant is non-collaborative behavior that is reinforced by many organization's culture or managerial practices. Many managers, by their attitude and behavior, promote rivalry and even conflict between team members. This is symptomatic of a command-and-control management style as I discussed previously (see Production Line Mentality).

Managers often realize that what they do and say has detrimental effects and try to change their behavior. However, this can be difficult when  motives are questioned. For example, common advice is "Praise publicly, criticize privately" - but this can backfire. Of course, you should never criticize publicly - it is demoralizing and humiliating - but (too much) public praise may not be seen as genuine and may trigger envy in other team members. A sudden change in behavior will also be viewed with suspicion unless there is evidence of a change of attitude. Above all never say one thing and do another.

Praise privately   

It's commonly said to "criticize privately but praise publicly". My own policy is to give all feedback to employees privately - both criticism and praise.

Of course (unless you are very good a deception :) it should also be honest, otherwise it is simply seen as manipulative.

Admittedly, it is nice to ensure it is known publicly when someone has done a good job.
In addition, many companies have policies that work against team work. For example, such things as Annual Performance Reviews and Employee of the Month awards usually have little effect apart from causing resentment. But when they do have an effect it is one that promotes competition and rivalry which actually undermines collaboration.

Why Teams Should Collaborate

We have seen how the personality, training and years of conditioning make it difficult for developers to work together - so why don't we give up on the idea of an highly-collaborative, self-organizing team?

Don't give up! If we can overcome the above problems then there are big advantages. I have been expounding these advantages (and the disadvantages of a command-and-control no-collaborative approach) in all my posts since last December (except for Lean is Not Agile).

In summary they are:
  • more creative ideas are generated
  • less coordination overhead
  • avoids many pointless activities
  • greater focus on giving the customer what they need
  • less specialization leading to greater productivity
  • specialists cannot hold the organization to ransom
  • greater adaptability to change
  • greater job satisfaction
  • greater productivity
In essence a good Scrum team will produce better results. Further, the results are often produced more quickly - or there is, at least, the perception of increased productivity because the team is focused on what is important to the customer - in the short term. In the long term there are definitely large productivity benefits.


In researching this post I found quite a few web pages arguing against small self-managing teams (eg: Does XP/Scrum Violate the “Agile Manifesto”?), Some of them have a point, but some are simply incorrect. I refined it to six basic points which I will now address.

1. Having many small tasks done by different people results in inconsistencies.

This will happen in any team, but in Scrum team members are actually more likely to work together to avoid these sorts of problems. For example, in almost all jobs I have had there have been coding standards "in use", but I have only ever seen them followed with any rigor in a Scrum team.

2. Group decisions are often not good decisions.

The team may be prone to "group think", but this is not due to Scrum. In fact, Scrum empowers individuals to make a contribution. The focus should be on finding the best solution, not going along with everyone else.

There will be occasions where there are differences of opinion on technical issues, but in my experience, when all team members are aligned, these are easy to resolve. Moreover, decisions are often not group decisions since generally Scrum teams have experts in different areas to whom they defer.

3. Decisions are slow because they are made by committee.

First, it is important to remember that a Scrum team is not a committee. Most committees are composed of members with very different agendas; whereas in a Scrum team all members should have the same focus.

Also, it may appear that a team is indecisive because they are using an important Agile practice of deferring decisions until necessary (see JIT). When the current backlog task dictates that a decision be made then a good Scrum team will not hesitate to decide (or give it to the expert in that area to decide).

4. There is no single person with the authority to enforce design consistency.

This is related to the previous points. The argument is that there is nobody in control who sees the big picture, which results in haphazard decisions and inconsistencies in the design. Common opinion is that it's better to have a single person with the vision to direct the project.

“Scrum...works better
than the single
visionary approach”
The truth is that the "single visionary" approach does not work well with a team of more than a few people. The people actually creating the software are continually twisting and changing the vision for many reasons. The visionary is flat out ensuring that her vision is implemented.

Scrum encourages a better approach where everyone sees, or at least has a grasp of, the big picture. It does not always work perfectly, but it works better than the single visionary approach.

5. The more you divide a task between people the greater the communication burden.

Again, this is simply a consequence of working in a team of more than a few people. Using Scrum and feature teams (an example of DIRE) actually reduces the communication burden.

6. There is no individual ownership and pride in work.

I talked about this last week (see the section on Code Ownership). You may believe, as I do, that you write perfect code, but with input from other team members it can be even better. Moreover, there are other disadvantages of ownership such as specialization, increased risk, etc.

Of course, taking pride in your work is a good thing. Knowing you have done a good job is immensely satisfying. What I didn't expect with Scrum is that I can be even more proud when my team does a good job.

Homo Habilis

One fundamental advantage that humans have is the ability to work in small teams. Humans are inherently social - far more than any other species. Much of this behavior (or tendency towards the behavior) is built into our DNA, due to our recent evolution over the last few hundred thousand or more years.

The formation of small teams was an important early step in human evolution probably beginning more than two million years ago when Homo Habilis began hunting in small self-organizing teams.

Many developers work for years, even decades, almost in isolation, which can be alienating. Many report having an immense feeling of satisfaction when they first work on a collaborative, high-performance Scrum Team. The problem is that not all teams are like that - in the next section we will try to fix that.

How to Encourage Collaboration

Collaboration is fundamental to Agile and Scrum in particular. Lack of a collaborative spirit is usually the reason that Scrum fails. So how do we fix it?

Scrum Practices

Scrum practices encourage collaboration. The visibility provided by the daily standup provides a feedback mechanism that keeps everyone on the same track (as well as providing motivation and peer pressure - see the discussion of the Ringelmann Effect in Scrum == Communism). The product owner, and particularly their product backlog, keeps everyone focused on the one thing - what the customer needs. Empowering the team gets them working together to come up with creative solutions.

XP Practices

Other Agile (not specifically Scrum) practices also help. Here are some examples from XP.

A common open work area for the team encourages communication. (See XP:Space)

A customer representative (eg, the PO in Scrum) works closely with the team. This not only allows the developers to obtain timely help, it also gives the customer invaluable insight into the development process as I explained in Customer Management(See XP:Customer)

Continuous integration means the developers are always working together to ensure that the system works and that code modifications are compatible. (See XP:CI)

One of the best signs of a good team is when programmers are happy to work on other's code and have other's modify their code. At the very least all code should be reviewed by at least one other person. If people get defensive about "their" code then that is a problem. Pair programming is the ultimate aim in this regard, and has the added benefit of producing better code. (see XP:Pair)

Related to pair programming is the idea of "collective code ownership". Nobody owns any piece of the code (or anything at all, actually), so anyone is free to modify any part of the code. Note that I do agree that often only the original creator(s) of a piece of code may be the only one to appreciate all nuances of the code, which is why Unit Tests are essential to ensure that changes do not introduce bugs. (See XP:Ownership)

Enhancing Team Spirit

Unfortunately, some teams just never "click". Usually the problem is the "mind-set" of one or more team members, as I discuss below. First we look at building team spirit which can be the first step towards changing a mind-set.

Here are 12 suggestions:

  1. encourage open and honest communication
  2. empower the team to make decisions
  3. communicate about strategic planning/goals
  4. encourage team members to trust each other
  5. make the most of the talents of the team
  6. never punish or humiliate team members for mistakes
  7. avoid behavior (like public criticism/praise) which promotes rivalry
  8. never compare team members against each other
  9. reward the team not individual team members
  10. encourage the team to be polite to each other
  11. encourage the team to eat together
  12. encourage the team to see the customer's point of view
Changing Mind Set

I guess the whole point of this post is that many developers have the wrong mind-set. They become defensive when their mistakes are pointed out. Alternatively they are reluctant to give feedback when someone does a bad job for fear of offending them or getting a bad reaction. People forget to give positive feedback when someone does a good job.

Somehow you need to encourage the team to be open and honest with each other. A collaborative environment where people bounce ideas off each other will produce the best possible software.

Here are 12 tips for team members:

  1. trust team-mates to do their job
  2. be open to new or different ideas
  3. take responsibility for committed tasks
  4. always find a way to make a contribution
  5. be open to helping in areas outside your expertise
  6. look at things from the customer viewpoint
  7. don't be defensive when someone points out a mistake or a better way
  8. don't hide your mistakes
  9. don't be afraid to give negative feedback BUT
  10. don't be offensive in pointing out other people's mistakes
  11. be polite and respectful
  12. never put personal ambition ahead of the project

As I discussed a few years ago (see Why Scrum Fails) the root cause of the failure of Scrum is the culture of the organization. The team will not change their mind-set if the culture discourages it.

First, managers need to relinquish their control, so the team can effectively self-organize. Rewards should encourage collaboration - ie, team rewards, not individual bonuses. Encourage the team to identify and fix their own problems.

Most importantly, it is important to drive out fear. People won't take risks if they are fearful of the repercussions when things don't go to plan.


Scrum is centered around the team - a small, stable, self-organizing, self-managing, collaborative team. When the team works well together Scrum works very well. When the team does not collaborate Scrum does not work well.

Unfortunately, many developers by their nature are not prone to collaborative behavior. Luckily this is not an inherent limitation but is a mainly a conditioned response due to years of working in an oppressive environment.

The advantages of removing an untrusting, blaming culture and overcoming developers defensiveness to develop a collaborative team are big. As explained above there are many benefits but in essence better results are produced, often more efficiently and with greater satisfaction to customer and developers.

Many of the practices of Scrum help to encourage collaboration such as the visibility provided by the daily standup and the focus provided by the backlog. Feature teams as discussed last week are also important. Further, other Agile practices such as continuous integration, collective code ownership, customer focus, collocation, etc are very useful.

The most important thing is to change the environment to one where the developers are empowered to do their best and rewards are team-based not individual.

Further, developers need to be open to the change and fight their defensiveness and preference for working alone. It may be surprising that working as part of a highly-functional small team can be deeply satisfying.

Friday, 3 April 2015

Scrum Team Composition

Last week we saw how important it was to get the size of a Scrum team right. This time I will look at another issue that is just as important - team composition or who to put on which team.

Of course, if you only have enough people for a single team this blog may not be relevant to you. However, there are things of interest such as a look at personalities of team members and how that affects collaboration. [Late note: I have split off the bit about collaboration into my next post, so I only cover it briefly here.]


The biggest problem I have found with the successful adoption of Scrum is team members who seem incapable of working effectively together. This can mostly be put down to personalities. First, different people sometimes just don't get along, for no obvious reason. This is why a bit of consultation, judgement and experimentation may be required when composing teams.

Typical developer personality profile
(provided by DISC Personality Testing)
More significant is that most developers generally have a personality type that rails against the collaboration inherent in Agile methodologies. If you are familiar with the DISC system of personality classification and assessment you may already be aware that software professionals are generally of the S personality type something like in the diagram. Importantly, for our discussion, it means they prefer to work alone. (However, I believe this is, at least partially, a learnt or conditioned behavior, as I discuss next week.)

This causes the sorts of problems you have probably seen, such as continual disagreement about approaches to technical problems. Less obvious is the developer who is uncooperative with Scrum practices or other areas of their work that they are unhappy with - they may be ostensibly open and helpful, and may not even be aware of their behavior and how it causes problems. Most important is how personality affects collaboration between team members.

Many companies adopting Scrum attempt to hire developers of the desired personality. This is why a lot of job ads emphasize the "team player" aspect. Some companies go as far as performing personality testing (such as DISC) on job candidates. I think this is the wrong approach as most developers can be encouraged to be collaborative given the right environment which I discuss next week.

Team Structure

I already talked about the different skills required (and not required) in an Agile development environment - see Agile Roles. What I did not cover is how to structure the teams, basically which people to put together in the same team. The basic rule is that you need all the skills in a team required to complete the tasks in the backlog of that team. I will elaborate on this below but first we look at why it is important.


A major consideration when composing teams is to reduce the costs of communication by putting those people on the same team that need to work closely together.
Component vs Feature Teams   

In Succeeding with Agile, Mike Cohn calls teams structured around the architectural design of the software Component Teams. He contrasts this with teams structured according to customer requirements which he calls Feature Teams.

See Succeeding with Agile [ISBN-13: 978-0-321-57936-2] pages 183-188.
The simplistic way to do this is to group people working on the same sorts of things - so you might have an analysis team, an architecture team, coding, testing, installation and support teams, etc.

The developers too are split into sub-teams based on different parts of the software they work on, Examples I have seen are a database team, services layer team, display engine, AI, comms, backend server, web interface, etc. In Agile jargon these are called Component Teams (see note at right).

Component Teams do not work well in an Agile environment, as we will see, but even in a traditional non-Agile project they cause problems like:
  • silo syndrome (see Production Line Mentality)
  • unnecessarily complex designs (see below)
  • contorted designs due to changes made in the wrong place
  • modules with unneeded features due to perceived future needs
  • over-specialization
  • uneven workload
  • dependence on multiple teams to meet a deadline
  • code ownership problems (see below)
  • narrow focus on a specific task/module
  • lack of focus on delivering what the customer wants
  • isolating people who often need to communicate
  • need for lots of "interface" documentation
  • a lot of integration testing work
  • requires a lot more planning
An alternative is to be customer-oriented when composing teams. Each team can focus on one or more aspects of delivering something useful to the customer - ie, Feature Teams. Feature teams are focused on completing tasks on the product backlog. Typically these would be about different aspects of the user-interface, but other things may be important to the customer, such as data-compatibility with their systems.

Software Design

Talking about software design may seem completely off topic here, but the design of a piece of software is closely linked to how the people creating it interact. Some say that organizational structure determines software architecture. It could be the other way around. In either case it is important for those involved in the system architecture to also be involved in the creation of the teams.

Interestingly, this relationship might also explain why the Layer Anti-pattern is so common. I have noticed the tendency of organizations with many layers of management to also develop software with lots of layers. The Layer Anti-pattern demonstrates poor or unnecessary separation of concerns which interferes with the ability of modules to communicate and adds to the complexity of the software. Analogously, a layered organizational structure interferes with collaboration. Both are examples of how a simplistic layered approach can work against the DIRE.


This whole discussion can also benefit from a consideration of the DIRE principle. Conventional thinking is that people doing the same things should be on the same team - a Component Team. Using the DIRE principle we compose teams in such a way that people who need to work closely together are on the same team. (In this case the team members are the "related entities" - see DIRE for more info.)

Further, this is a result of the Agile emphasis is on delivering useful features to the customer, by performing the tasks for a particular feature at once (or as close in time as possible). This is also an example of DIRE - in this case DIRE stands for "Don't Isolate Related Events".

Component Teams

Before we look at feature teams in detail let's cover how component teams work. Many of the deficiencies of component teams are due to developers employing "silo" thinking. See Production Line Mentality and Silo Syndrome for more on this -- but here I just discuss problems specific to software development.

Note that even teams that deal directly with the user interface may still be component teams. For example, the "GUI" team in the diagram below is a component team (as, of course, are the other two teams) since the development of most features would typically involve at least one other team.

Component Teams
In the following discussion I will discuss a theoretical component team with one or more dependent teams -- such as the Math Team in the diagram, which has the Services Team and the "GUI" team as dependent teams.


Using component teams tends to lead a project towards the dark side called BDUF (big design up front), which I hope you are aware is very bad and the antithesis of the Agile approach -- if not see Agile Design. Components developed like this are always overly complex, with many unneeded facilities. This makes the code harder to understand, harder to verify, and makes it less amenable to modifications. In my experience, the worst thing is that it's harder for the users of the component (ie, dependent teams) to understand how to use it (see Gas Factory Anti-Pattern).

premature decoupling
is a common problem
The Agile approach is to develop the bare minimum that is required to allow the customer to use the software. The very first usable version of a program may be ready in just a few days and have no discernible components. It will later be refactored by decoupling different parts of the design when necessary, and, significantly, when it is more obvious how to best do so. Premature decoupling is a common problem even in Agile development.

If the team is certain of the best way to decouple (and that decoupling is even necessary) then it can be useful to create a simple component early in the evolution of the software. This simple component will initially be very small (perhaps only a few lines of code) but will be added to and refactored over time, as backlog items dictate.

Over time, components tend to be "owned" by one team (or even one individual). If other teams need changes to the component then they depend on the owner to deliver those changes. The component team then tries to anticipate what dependent teams will require to avoid the dependencies interfering with sprint commitments. As I have mentioned in the past, lots of other unnecessary stuff creeps in when the "owner" is focused on the component and not the backlog - eg: things that are "trivial to add and nice to have", "will definitely be needed eventually", etc. Moreover, these "bonus" features add to the debugging, testing, and planning burden, but most of all they make it harder to refactor the code and make the changes that are actually needed.

components tend
to be owned
by one team
Apart from BDUF, there is the problem that component teams naturally tend to focus just on the component, instead of the backlog items (ie, what the customer actually wants). They will have an idealized picture of what the component should do that is out of tune with what is really needed. They need to focus on customer requirements not component capabilities.

One consequence is that the dependent team(s) often have to make do with a component that is not really suited for what the customer needs. This results in a misshapen design which inevitably leads to bugs, complexity, and difficult to maintain software. This is a major reason why software degrades over time and has to be written from scratch (see Why Good Programs Go Bad).


I once worked for a company which had developed a world-leading piece of software that was heavily reliant on the display and manipulation of 2-D graphical objects. The company had developed a remarkably useful library for 2-d computational geometry. They had the good fortune to have a team of mathematicians who were also good C++ programmers who had created this component.

One of the most powerful features of the software was the display and manipulation of text. Among the text options was the ability to display text on many different base-lines: straight lines, lines at any angle, along a Beziere curve, etc. One of the base-line options was the ability to place the text on the inside or outside of a circle or ellipse. Of course, the geometry library provided an ellipse class which was used for many things and was the obvious thing to use for this type of base-line.

Like all the graphical objects you could apply an affine transformation to the ellipse class - for example, to move, rotate, enlarge, etc. The problem with using an ellipse as the base-line for text was that when it was transformed it was impossible to determine how it had been transformed. Even if you knew the before and after you could not determine what transformation had been applied. For example, an ellipse that was elongated in the X direction could be transformed into an ellipse elongated in the Y direction either by rotating it 90 degrees (or 270 degrees) or by reducing the X scaling and increasing the Y scaling.

In order to transform the text to match the base-line you had to know where each point on the ellipse had moved to. This was impossible to do if you only had the before and after ellipses to work with.

Unfortunately, the "geometry" component team were unwilling to modify their perfect ellipse class to facilitate its use as a base-line. The result was a kludge at a higher level in the code which caused bugs and maintenance problems.

Code Ownership

Component teams can become very protective of their work. I have seen some go as far as not making the source code available outside the team. Even if they do release the source, it may be strictly forbidden for anyone outside the team to make changes to the component, or even submit code to be included in the component. Change requests often need to be submitted in writing and can take months to be considered, approved and (if you're lucky) implemented.

As you can imagine, and may have even experienced, this can be very frustrating to a dependent team dealing with a customer who expects responsive changes. The component team may be unavailable, too busy, or simply not interested in making the change. A common problem is that the component team is unwilling to corrupt the purity of their component by acceding to the whims of the customer! Does this sound familiar?

One of the principles of XP (the guiding light in these areas of Agile development) is that there should be no code ownership (see Collective Code Ownership). Any team should be able to make changes to any of the code that is available to them. Of course, that is not possible with third party components without source code - but that is just another argument for the use of open-source libraries.

The key thing is that, if modifying the component requires specialist knowledge then each team needs at least one developer (even if shared) with that knowledge, or needs to acquire the knowledge. (Of course, the need for lots of specialists is symptomatic of a non-Agile environment as I discuss below.)


There was once a company with a software product that dominated it's market throughout the world. It was used by some of the largest companies. Most of these clients required a high degree of customization of the software to suit local markets, regulations, etc.

This was a large piece of software based around the template design pattern - essentially a "core" system with many extension points. The "core" component was tightly controlled by the main development team at the head office of the company. Several on-site customer teams used the extension points to customise the software to individual customer requirements.

* This configurability came at a large cost. The main problem was that it added a great deal of complexity making it hard to understand and modify the system. This also had knock-on effects such as poor performance.
However, despite it's immense configurability* there were many customer requirements which could not be accommodated, and required (or should have required) core changes. As you can imagine, it was extremely difficult to get timely changes made to the core system, if they were done at all. Scheduling conflicts meant that requests for changes needed to be submitted many months in advance. The teams at client sites found the core team arrogant and uncompromising. The core team were upset at the barrage of stupid and conflicting requests.

Inevitably the integrity of design became compromised. Many facilities were simply tacked on to client systems rather than being properly implemented in the core. This contorted the design and created maintenance problems. Moreover, the same thing was often implemented by different client teams in different ways - an obvious violation of DRY.


Component teams require a lot of coordination and planning to ensure that the components work well together and the development of all components is on schedule. (A great advantage of Scrum is that it requires much less planning work.)

Integrating components and integration testing is also required, but if coordination (and documentation - see below) between teams is inadequate then integration tasks can blow out enormously.

Using component teams also makes it far more likely that deadlines will be missed. It only takes one team to be late for the whole project to be delayed.

Component teams are also more likely to suffer from uneven workload. Sometimes they have little to do; other times they are overloaded due to different dependent teams waiting for critical functionality. Component teams will invent work if they have none, which can be good if it is refactoring the code to improve its quality (maintainability, efficiency, etc), but it is often unrelated to any current customer requirements.

A common scenario with highly-specialized component teams is that they are formed near the start of a project then quickly complete most of the required functionality, whence the team needs to be down-sized or even disbanded. This can lead to valued developers leaving the organization because it seems that their work is complete and they have nothing much of interest to hold them. Alternatively, the organization will start inventing work for the component team - but this work tends to become less and less customer-focused.

A project using component teams often needs to be reorganized which is counter-productive. The truth is, it's hard to build a good team that works well together - at least partly due to personalities (see above). Once you have a well-functioning team you don't want to change personnel too often. Many Agile teams can go unchanged for years, pumping out quality software.

Agile teams can
go unchanged
for years
A big problem for a Scrum team working in a large organization is "external dependencies". Scrum teams will strive to finish their sprint backlog by the end of the sprint but are continually frustrated by being dependent on people outside the team. If you have this problem then it indicates that the teams are not really feature teams.


Component teams tend to produce lots of documentation, since they need to explain the interfaces so that other teams can use their component(s). Of course, as you know, Agile favors "working code over documentation". We all know the problem of documents (time-consuming to create, difficult to understand, incorrect, out of date, etc), so how can we avoid this problem?

Another Agile principle, continuous integration, means there is far less need for documentation. If the component and the code that uses it are developed at the same time (by the same team) then this avoids the need for documentation, hand-overs, integration testing, etc. Continuous integration works far better with feature teams than component teams.

Continuous integration and feature teams work together to reduce the need for large amounts of documentation.

Feature Teams

Feature teams are a different way to structure a project. Here we try to avoid having a team that is dependent on any outside person or team in order to complete their backlog items. After all it's only the members of the Scrum team who are completely focused on meeting the sprint objectives.

feature teams
can and
should specialize
Note that there is some dispute about what constitutes a feature team. This is caused by some people insisting that feature teams do not specialize. The fact is that feature teams can and often should specialize.

For example, a common definition of a feature team (which I believe is inadequate) goes something like this:

A cross-functional team that has all the skills required to complete items from the product backlog.

This definition implies that all feature teams are equivalent since they must be able to complete many or all items from the product backlog. It assumes that the product backlog has, and always will have, items of a similar nature.

Feature Teams
The problem is that real-world projects have backlog items of amazing variety. Consequently, different feature teams can, and probably should have different capabilities. I discuss this below under Specialist Feature Teams.

The diagram at left takes the members of the three component teams (in the component teams diagram above) and creates three feature teams. Note that there is a specialist "Charts" feature team which is the only team that requires developers with knowledge of the geometry library and the charting component.

Specialist Feature Teams

A feature team can specialize as long as it specializes in things that are important to the customer. As an example you might have a feature team that does not deal with the user interface; instead it handles interfacing with other client systems since it may be critical for the customer to get up-to-date information (eg, inventory levels). A team concentrating on this area of the software would have specialist knowledge very different to that of feature teams dealing with the GUI.

should be
long lived
Of course, even such a specialist feature team should not be so specialized that they can't work on other general backlog items.

We also need to keep in mind that feature teams should be long lived. Before creating a specialist team it should be fairly certain that they would have an ongoing supply of high-priority backlog items to suit their speciality.

Scrum Jargon       

Product Backlog: prioritized list of tasks for the project

Backlog item (PBI): a single task on the product backlog
General item: a backlog item that can be taken by any feature team
Special item: a backlog item to be taken by a particular feature team
Team Backlog: Subset of product backlog allocated to a specific team
Sprint backlog: the items that a team commits to complete in a sprint
Specialist team: preferred team to deal with special items


Feature teams are a great example of DIRE. They promote collaboration by getting people who are responsible for a feature to work closely together.

This collaboration has the advantage that the team members are all focused on a common goal rather than their own small area of interest. Moreover this focus (on high-priority backlog items) is of direct relevance to the customer.

This sort of collaboration helps avoid the Silo Syndrome (see Silo Syndrome in Production Line Mentality) and over-specialization (see below). It also addresses coordination overhead by greatly reducing the need for written documentation, etc.

Evolutionary Design

The basic Agile approach is that changes are made in small increments, so that the software gradually evolves into what the customer wants. By taking "small nibbles", slow but steady progress is made. The overhead of large hand-overs is dramatically reduced and integration problems eliminated. Further, the customer is happier because they can see what is happening. (There may even be a perception that the development took less time than it actually did.)

evolutionary design
is easier
using feature teams
The only advantage to taking "large bites" instead of "small nibbles" is from economies of scale. However, (as I already discussed in Agile Design) this is far outweighed by other problems like reduced visibility. To continue the analogy, there is a tendency to bite off more than one can chew.

However, each small nibble may possibly involve changes in many different areas of the code. Hence a team requires all the skills to make the changes. That is, evolutionary design is easier using feature teams.


A big problem with a lot of software, especially much legacy software, is that it can only be modified by a small group of specialists. Whether this happens intentionally or not, it works as a form of job preservation for them. Due to a poor design and a lack of documentation only the "gurus" who understand how it works can modify it; these are usually those who wrote the software in the first place. (Note that by "poor design" I may simply mean that it is unnecessarily complex, though typical legacy applications have many other problems.)

These specialists are only required due to the complexity of the design. It's usually not that the component is performing an inherently difficult process; it is simply the way it has been designed and built (and not documented).

Feature teams are far less likely to create such components since there is no code ownership. An underrated advantage of feature teams is that they reduce dependency on these "specialists".

Finally, consider the worst case scenario. This is where somebody (usually an existing component team) decides to build an in-house component, rather than use a perfectly adequate off-the-shelf or open-source one. Typically the project must then deal with an expensive-to-implement, poorly-documented, hard-to-use component for little, if any, advantage. A feature team is focused on giving the customer what they want, as simply as possible, so is much more likely to go with the open-source solution.

Feature Team Problems

Using feature teams does increase the likelihood of conflicting code changes, but this is not a major problem especially if you take my advice and allow some team specialization. Often conflicting changes can be merged with little or no problem. Sometimes it may require a few team members from different teams to get together and work out how to combine the features. Occasionally the teams may need to go back to the PO(s) to point out conflicting requirements.

One thing that worries many people is that they think chaos will ensue if all developers can modify any of the code - the fear is that the quality of the code will rapidly degrade. This simply does not happen as long if there is someone on the team with the skills needed to do a proper job. (If a team member must make changes outside their area of expertise then it should be carefully reviewed by the relevant expert.)

One problem is if there are not enough specialists for all the teams. In this case specialists should be shared between teams, and encouraged to pass on their knowledge. (But remember, as I discussed above, feature teams do not tend to create components that require specialists anyway.)

Task Allocation

Once you have multiple feature teams the next problem is how to assign tasks to the different teams. This depends on your PO(s) (product owners). If you have a single product owner for all the teams then you need a single product backlog from which all teams derive their own team backlogs.

Even with multiple PO's it is beneficial to maintain a single product backlog for the project. Of course, this requires the PO's to meet to work out the relative priorities of all items and assign them to different teams. (This can be difficult with vastly different items, like comparing apples and oranges.) As an example, the diagram above shows a product backlog split between three teams.

In doing this it is important to carefully consider the task assignments, depending on the work-load and experience of the teams. For example, the same team should probably perform related items from the same Epic. In the diagram you can see that the Charting Team has enough high-priority Charting Tasks, but if they didn't they would need to work on other tasks like the General items. The PO(s) should ensure that each team has enough tasks in their backlog for at least two sprints (based on rough estimates given in grooming).

One obvious, but important point, is to ensure two teams do not accidentally end up working on the same task.


This case study concerns a Scrum team (one of several) in a large company, tasked with supporting and maintaining a legacy application running in thousands of locations. The software was highly configurable (and regularly configured). Apart from the PO and SM the team members were:
  • 5 testers
  • 4 configuration experts
  • 3 developers (coding in 3 different languages)
  • 2 business analysts
Most of the PBIs (product backlog items) were configuration changes - requiring configuration experts, testers and often a business analyst, but no developers. Apart from config. PBIs there were also PBIs for small software changes and occasionally large developments - mainly requiring coding but with possible involvement from anyone in the team. Even if there were no software enhancements in the product backlog there were always low-priority (usually historical) bugs to fix.

The product backlog typically contained mostly configuration and general tasks with a few low-priority bug fixes (see Typical Product Backlog in the diagram). For a fortnightly sprint the sprint backlog would be composed of the highest priority tasks (mainly config) plus a few development tasks to give the coders something to do.

However, there were sometimes high-priority developments, in which case the product backlog would look very different (see "Development" Backlog in the diagram).

The major problem that the team experienced was due to the mix of tasks. Most of the time the high priority tasks were configuration and of little or no consequence to developers. Sometimes there was a major development that was of no interest to most of the configuration experts. In most meetings (planning, standup, grooming) there was a lot of discussion that was only understood by a subset of the team, which meant there was a huge amount of time being wasted by people in meetings that were not important to what they were focused on.

Component Teams
There were other problems such as many tasks being highly dependent on external people - indicating that this was not really a feature team. Another thing was that the configuration guys preferred to have a standup at 8:30am, while the developers preferred 10:00am. It was also demoralizing for the developers to be continually handed low-priority "scraps".

It was obvious (not just because the team was too big) that the team should be split into multiple teams. So how would you split up the team?

It was suggested to use a team structure of Testing, Configuration and Development teams.  This was similar to the teams that existed before we adopted Scrum. See the Component Teams diagram above.

Feature Teams
A better approach would be to create two (or even three) feature teams to deal with the types of backlog items that were commonly encountered. The approach I recommended was to have a Configuration Team that dealt with configuration backlog items and a Development team that would deal with programming tasks (and other tasks if there was not enough development). See the Feature Teams diagram at right.

Each team would have their own backlog derived from the product backlog (see diagram below) and would not have to deal with meetings and discussions about tasks that they did not need to focus on. (Of course, that did not mean whatsoever that communication between the teams was discouraged, when necessary.)


An important part of implementing Scrum is to carefully choose the composition of teams.

First, it is important to consider personalities when building teams. This requires good judgement and a measure of luck to get right. Don't be afraid to experiment and change teams around if things are not working.

From an Agile standpoint it is also important to get the skill mix right. Scrum teams should be formed around customer needs not around the software architecture -ie, use feature teams not component teams. One of the most frustrating things for a Scrum team is repeatedly failing to complete sprints due to external dependencies.

As well as creating external dependencies, component teams also:
  • need more planning and coordination effort
  • tend to produce overly complex designs
  • create and depend too much on specialists
  • focus on their own small world instead of the big picture
In contrast, feature teams encourage collaboration and avoid the problems of component teams. Amongst their advantages are such diverse elements as:
  • keeping all team members focused on the customer
  • making specialization less likely (see Production Line Mentality)
  • putting together team members that need to work together (see DIRE)
  • allowing teams to work without being frustrated by external dependencies
  • focusing on only delivering what is required now (see Fifth Element)
In brief the rules/attributes for feature teams are:
  • the team has all the skills to tackle tasks on their backlog
  • every team member could make a contribution to each backlog task
  • specialist teams are useful if the backlog has different classes of PBIs
  • you anticipate enough special items to justify creation of a specialist team
  • feature teams are stable and long-lived
  • feature teams are highly collaborative and focused on the customer
Next week I will look at personalities and why teams do not collaborate.