Patterns For Collective Code Ownership

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Following the somewhat schizophrenic challenges of dealing with person issues on collective code ownership, here we focus on the practices and practical aspects. How do we technically achieve collective ownership within teams?

We’re using the “simple pattern” approach again. For each pattern we have a suitable “anchor name”, a brief description and nothing more. This should be plenty to get moving  but feel free to expand on these and provide feedback.

Here’s the basic set of patterns to consider:

Code Caretaker

Let’s make it a bit less personal, encourage the team to understand what the caretaker role for code entails. It’s not a single person’s code – in fact the company paid us to write it for them. Code does still need occasional care and feeding – Enter the “Caretaker”.  Be wary though that caretakers may become owners.

Apprenticeship

Have your expert spend time teaching & explaining. An apprentice learns by doing – the old-fashioned way under the tutelage of a master craftsman guiding them full-time. This is time and effort-intensive for the pair involved but (unless you have a personality or performance problem) is a sure-fire way to get the knowledge shared.

If you need to expand to multiple team members in parallel,  skip forward to feature lead & tour of duty.

Ping-Pong Pairing

Try pair programming with an expert and novice together. Develop tests, then code, swap places. One person writes tests, the other codes. Depending on the confidence of the learner, they may focus more on writing the tests and understanding the code rather than coding solutions. Unequal pairing is quite tricky so monitor this carefully, your expert will need support in how to share, teach & coach.

Bug Squishing

Best with large backlogs of low-severity defects to start with. Cluster them into functional areas. Set a time-box to “learn by fixing” – delivery is not measured on volume fixed but by level of understanding (demonstrated by a high first-time pass rate on peer reviews). If someone needs help they learn to ask (or try, then ask) rather than hand over half-cut. This approach works with individuals having peer review support and successfully scales to multiple individuals operating on different areas in parallel.

A Third Pair of Eyes (Secondary Peer Review)

With either an “initiate” (new learner) or an experienced developer working on the coding, have both a learner and an expert participate in peer reviews on changes coming through – to learn and provide a safety net respectively. The newer developer should be encouraged to provide input and ask questions but has another expert as “backstop” for anything they might miss.

Sightseeing / Guided Tour

Run a guided walk-through for the team – typically a short round-table session. Tours are either led by the current SME (subject matter expert) or by a new learner (initiate). In the case of a new learner, the SME may wish to review their understanding first before encouraging them to lead a walk-through themselves.

Often an expert may fail to identify and share pieces of important but implicit information (tacit knowledge) whilst someone new to the code may spot these and emphasize different items or ask questions that an expert would not. Consider having your initiate lead a session with the expert as a backstop.

Feature Leads

The feature lead approach is one of my favourites. I’ve successfully acted as a feature lead on many areas with teams of all levels of experience where I needed to ramp up a large group on a functional area together.

By introducing a larger team, your expert will not have the capacity to remain hands-on and support the team at the same time. They must lead the team in a hands-off approach by providing review and subject/domain expertise only. This also addresses the single point of failure to “new” single point of failure risk seen with “apprenticeship”.

This is also a potential approach when an expert or prior owner steps in too frequently to undo or overwrite rather than coach other members activities. By ensuring they don’t have the bandwidth to get too involved you may be able to encourage some backing-off but use this approach with care in these situations to avoid personal flare-ups.

Cold Turkey

For extreme cases where “you can’t possibly survive” without a single point of failure, try cold turkey. Force yourself to work without them.

I read an article some years ago, (unfortunately I can’t track it down now) where the author explained how when he joined a project as manager, the leaders told him he must have “Dave” on the project as nobody else knew what Dave did. He spent a week of sleepless nights trying to figure out how to get Dave off the project. After removing Dave from the project, the team were forced to learn the bottleneck area themselves and delivered successfully.

(Apologies to any “Dave”s I know – this isn’t about any of you)

Business Rule Extraction

Get your initiate to study the code and write a short document, wiki article or blog defining the business rules in the order or hierarchy they’re hit. This is usually reserved for absolute new starters to learn the basics of an area and show they’ve understood it without damaging anything. It is however also a good precursor to a test retrofit.

Test Retrofit

A step up from business rule extraction whilst delivering some real value to the team. Encourage your learner to write a series of small functional tests for a specific functional area by prodding it, working out how to talk to it, what it does and what we believe it should do. Save the passing tests and get the results checked, peer reviewed and approved.

Chances are you might find some bugs too – decide whether to fix them now or later depending on your safety margin with your initiate.

Debt Payment

After a successful test retrofit, you can start refactoring and unit testing. As refactoring is not without risk this is generally an approach for a more experienced developer but offers a sound way of prizing out functionality and learning key areas in small parts.

This is also a natural point to start fixing any bugs found during a test retrofit.

National Service (also known as Jury Duty)

Have a couple of staff on short rotation (2-4 weeks) covering support & maintenance even on areas they don’t know. This is generally reserved for experienced team members who can assimilate new areas quickly but a great “leveller” in cross-training your team in hot areas.

Risks are generally around decision-making, customer responsiveness, turnaround time and overall lowering of performance but these are all short-term. I’ve often used this approach on mature teams to cross-train into small knowledge gaps or newly acquired legacy functional areas.

My preferred approach is to stagger allocation so that you have one member on “primary” support whilst another provides “backup” each sprint. For the member that covered primary in sprint one, they’re on backup in sprint 2. (expand this to meet your required capacity).

3-6 months of a national service approach should be enough to cover the most critical functional gaps on your team based on customer/user demand

Tour of Duty

Have your staff work on longer term rotations (1-6 months) working on a functional area or feature as part of a feature team. This couples up with the “feature lead” approach.

Again, this is an approach that is very useful for mature agile teams that understand and support working as feature teams but can be introduced on less-experienced teams without too much pain.

The tour of duty can also work beyond an individual role. For example a developer taking a 3-6 month rotation through support or testing will provide greater empathy and understanding of tester and user needs than simply rotating through feature delivery. (My time spent providing customer support permanently changed my attitude toward cosmetic defects as a developer)

Adjacency

This takes a lot more planning and management than the other approaches described but is the most comprehensive.

From the areas each team member knows; identify where functional or technical adjacent areas lay and then use a subset of the approaches described here to build up skills in that adjacency.

Develop a knowledge growth plan for every team member sharing and leveraging their growth across areas with each other. Although this is an increase in coordination and planning, the value here is that your teams get to see the big picture on their growth and have clear direction.

All these patterns have a selection of merits and pitfalls. some won’t work in your situation and some may be more successful than others. There are undoubtedly more that could be applied.

Starting in your next sprint, try some of what’s provided here to developing shared ownership and knowledge transfer for your teams. Pick one or more patterns, figure out the impacts and give them a try.

(Coming soon “Building a Case for Collective Code Ownership” – when solving the technical side isn’t enough)

Escaping the Oubliette (Part 2) – Tailing

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Following my previous articles on topping and debt prevention, we’ll now focus on the easier parts. How to clear old defects and debt. we’ll cover 4 simple strategies; 2 for defects and 2 for debt. (there are paired similarities across these).

For defects, we’ll focus on:

For debt we’ll focus on:

Unlike prevention and stop the bleeding activities which often require significant effort and commitment to accomplish, defect and debt removal have some simple and relatively low effort options. There are some high-effort/impact alternatives that we’ll cover later.

Today we’ll look at…

Tailing & Ratcheting

When you have a build up of defects over time you tend to have a “tail” of really old defects and issues. These are usually low or medium severity/priority items (with the occasional blip) and are often in functionally gray areas requiring difficult decisions or significant rework.

They age because we don’t want to touch them and would rather forget about them (the oubliette again). A typical defect age distribution looks something like this:

right-skewed beta distribution

right-skewed beta distribution

It’s one of the most common statistical patterns I see in software development (and I’ll return to it in future) but for the purposes of this article, I want to look at the “tail” of this curve- that last 5-10% of your defect population – all your oldest items.

Addressing the tail is pretty straightforward. You can either set yourself a target “maximum defect age by a given date” or simply focus on continuous improvement. Whilst the target approach gives you a clear goal, you risk setting yourself up for failure or under-commitment. Defects are considered notoriously hard to size (I’ll cover this myth in future) but chances are if they’re old they’re probably a bit tricky too so being predictable about dates is something you might prefer to avoid for starters.

Whether you aim for a specific target or improving every day/week/month you’ll need the same stepped approach.

Identify your oldest defect, pick it off the end of the queue and commit to closing it quickly and fairly.

Here’s the first thing to accept… Closing doesn’t mean fix it in every case. Because you’ve not touched it for a while, chances are someone is expecting a solution so you’ll be looking at a difficult conversation if you don’t fix it but that might be far easier than “fixing” something that shouldn’t be changed or will derail your team and product. Make open, fair, honest decisions in each case.

  • If it is something you think you should be fixing, get on with it.
  • If it’s not – close it

Sound familiar?

Aim to close at least one of your oldest defects every week or every sprint.

If you have a lot of items that are considered old, consider increasing your capacity on these in the short term to get the ball rolling. (at the cost of other delivery activities)

If we look back to your distribution of defects over time, when you do close out your oldest defects, put a ratchet mechanism in place that sets a continuously reducing maximum age.  In very bad weeks the ratchet may not improve but don’t let the numbers get worse again or the effort and good faith from your teams and management will have been wasted.

With a ratchet, remember each “notch” is a step change from the last point. For example if your last point was 1000 days(!), clearing everything older than that should leave some defects nearly 1,000 days old. Set the next ratchet point to 950 days (rather than 997), determine what falls in that next block (950-999) and fix those. Ensure each ratchet point is a larger time window than your execution period otherwise you’ll end up stationary. (I usually go for a ratchet up of 50 days improvement per week or sprint).

Here’s what I mean…

Defects Tail

Ratcheting out the oldest defects each week

3 months of this tailing practice every week will dramatically reduce the average and maximum age of issues in your queue. It’ll make you all feel better and it usually helps to draw the heat off on escalations for a while. (Bear in mind you should be doing this in addition to your “topping” approaches).

Occasionally you’ll reopen some old wounds this way but paying these some attention now stops them coming back up when the timing isn’t under your control.

Keep this up for six months or a year and you’ll reach a stable point where nothing gets too old and your team becomes adept at having difficult conversations with your customers early and backs them up with some successes as well.

Eventually in order to keep the ratcheting improving you’ll have to commit more people. This probably means you’re approaching your natural level of control or entitlement where you have aging defects levelling off and others being addressed in a reasonably consistent manner. It’s up to you whether you aggressively pursue the numbers down further or sustain them at this level.

In case this sounds too obvious or simple to work, I’m working with a team right now that introduced this ratcheting approach less than a month ago. We’ve reduced our oldest defect age by over 25% and customer escalations are consistently lower already. Perhaps most important to the team; we’re no longer at the top of the charts when our leaders review the defect stats. Although harsh-sounding. Sometimes, having someone else drawing the heat for a while lets us get back to focusing on value and priorities.

In part 3 we’ll look at an old favourite – the “bug blitz” or feel free to skip to part 4 – “the litter patrol“.

Escaping the Oubliette (Part 1a) – Debt Prevention

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This is a partial re-post of Escaping the Oubliette (Part 1). I’ve split the article into smaller readable components.

Great, I’ve got my incoming defect strategy nailed,

Now how do I prevent defects and debt in new code?

In 5 words…

Continuous attention to technical excellence.

Here’s my top 7 (there are plenty more)

  1. Acceptance Criteria – Be really disciplined on your acceptance criteria & acceptance tests, team up with Analysts, Testers, Product Owners if you have them and attack your stories from every angle. A good approach to this is a “story kick-off” where the whole team dismantles a story before starting.
  2. Thinking Time – don’t just start coding right away, task things out, try the 10 minute test plan, discuss your approach with your peers and for more complex or large items, try the “just enough design” approach.
  3. TDD – It’s hard to start but has an immense impact.  I’ve just seen a team complete their first project using TDD. 3 weeks into their final round of post feature-complete testing, their defect run-rate hasn’t had the testing spike seen on prior projects. In fact they’re keeping on top of all new incoming defects and have time to start paying down the historic backlog.
  4. Pair Programming – Do it in half-day trial chunks if you don’t have the stomach for going full-tilt. I’ve performed remote pair-programming with colleagues across the Atlantic using decent phone headsets and online collaboration tools for hours at a time. The net result of 2 days of remote pairing was finding and fixing about 10 extra defects in a thousand lines of code that neither of us would have found coding alone.
  5. Peer reviews – there is still a huge space for these in agile teams. But here’s the thing. Be really tough. A peer review is not a hurdle. It’s a shared learning exercise. Functional correctness is actually the smallest component of a peer review. You should trust your developers that far. But there’s a whole series of other aspects to review. See the joy of peer reviews.
  6. Small tasks – I once worked with an outsourced team who when taking work would disappear into a hole for 2 weeks and return with a single task in our configuration management system containing edits to 200+ files and multiple condensed edits to the files. My rule of thumb is one reviewable task per activity. If you’re going to add new functionality and refactor, that’s 2 independent tasks that can be identified and reviewed separately. This means you should be able to easily deliver 2 reviewable, closable tasks per day.
  7. Fast Builds – make it insanely simple for a developer to perform an incremental build that validates new code against the latest main code line. (small tasks are a big help here).  This includes the right subset of unit and functional tests. Aim for a target of a 30 second response time or less between hitting the button and seeing the first results.

In the next article in this series I’ll focus on “Tailing” – How do you start reducing the old defects.

Your Baby Might Be Ugly

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Everyone thinks their own babies are beautiful. Some probably are but there are plenty that really aren’t. In fact I remember one particularly interesting comment -“ugly people produce ugly babies”

This happens in code too.

Collective code ownership has many challenges. Here I focus on the person pitfalls.

Imagine you’ve just spent the last 3, 5, or even 10 years nurturing and grooming an insanely complex (and dare I say “clever”) functional area of a product. This has been your working heart and soul for years – apart from the occasional customer to distract you. It follows your own unique,  “perfect” coding style and conventions. You’re so damn good you don’t need unit tests, you instinctively know and understand every intricate tracery and element of logic in there.

Why then if it’s so perfect are you not willing to share?

This is where “Bad Captain” starts to kick in with me…

  • Do you believe that every other developer in the building is less capable than you?

(OK, sometimes it might be true but that’s very rare.)

– That’s fine, you can peer review and provide feedback if they don’t meet your standards right? It might be an emotional lurch to start with but seeing someone else succeed and recognize your greatness must surely be rewarding right? I’ll help you if you need.

  • It’ll always be quicker if you work on it. It’s just a waste of time and effort to train someone else up.

– Sure. Except if we had 3 or 4 people capable of working on it in parallel we might get everything that’s on the wish list for it done this year and you might be able to do that other interesting stuff that the rest of the team have been playing with. In fact, I’m willing to invest if it’s that important…

Bad Captain starts to twitch…

…and if it’s not, why do I have someone who believes they’re “one of the best” working on it – I want my “best” people on my priority tactical and strategic items.

  • You’ve been doing this as your own pet-project on the side and it’s not ready to share.

– If it’s important I want a team on it. I’ll happily lobby for some strategic investment. If it’s not as important as anything else we have committed right now I want you helping the rest of the team out…

Bad Captain…

– even if you’re good, you’re not “special”, don’t expect to be treated any differently than the rest of the team.

These first reasons are almost valid. But not good enough for me. The more of these I hear the more I start to twitch, the more terse I get and the more I start to frown and tense up.

Suddenly it’s too late! Captain Hyde takes the helm!

Here’s why Captain Hyde thinks you’re not sharing…

  1. You’re lazy, you’re only any good at this one area and don’t want to have the responsibility of teaching it or learning something new that you’re not so good at. – Time for you to learn a bit about intellectual humility.
  2. If you relinquish control of this code, you relinquish your seat of power, you’ll make yourself dispensable and that can’t possibly happen, you think you’re far too important for that. – I believe in good people, if you’re one of them I’ll fight to keep you. If there’s a squeeze, even the indispensable will get the push. In fact in my experience, the all-rounders are more likely to find new homes.
  3. Secretly in your heart you know it’s loaded with technical debt, years of warts strapped onto the sides, a catalogue of compromises and mud that doesn’t mirror the patterns of the outside world in the 21st century. – In fact I could probably find something open source that does the same thing. Quite frankly it’s an ugly baby that should have been put up for adoption or surgery years ago but your professional pride won’t admit it.

Captain Hyde can’t think of any good reason other than personal self-preservation or embarrassment that someone who is a single code owner would be unwilling for other people to work on and learn their code.

Maybe I’ve just been in management too long but I distinctly remember in my early coding years a call with a colleague in San Francisco where he said:

“Damn, you’re the only guy in the world that knows this stuff man”.

– at which point I felt that little clench inside that said. “I need to find and train my replacements up as soon as I can!”

A similar counterpart of mine in the US at the same time got thrown another pile of stock options every time he threatened to leave – that wasn’t my style as a developer and it’s not my style as a manager either.

Now despite all this ranting, there is another very real problem.

Developing collective code ownership from single points of failure on complex products is time-consuming, expensive and probably not what my business stakeholders want my team “wasting” their time on when we already have experts who are “perfectly capable of maintaining this themselves”.

It’s a fair point.

With a team who are willing to share but have no slack, if I want collective code ownership to succeed I’ve got to be able to market it properly.

Escaping the Oubliette (Part 1) – Topping

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As promised, how to Escape The Oubliette

So here you are, part of a team at the bottom of the defect & debt pit. What now?

The simple fact is, there’s no one answer but there are a selection of tools and there is a key.

The key comes courtesy of a comment from Jim Highsmith during one of his sessions at Agile 2010 – my paraphrasing below…

“Teams facing technical debt need both debt reduction and debt prevention strategies.”

When teams face technical debt they pick away, removing it piecemeal. After all, you have to eat an elephant one bite at a time right?

Trouble is, that only works if the elephant isn’t growing as fast as you’re chewing.

You need a two-pronged attack – what I like to call “topping and tailing”. The “top” is all the incoming issues and build-up of new debt. This is where you need to stop the bleeding. The “tail” is the backlog of existing debt. It’s already there – gently rotting in the corner of your product.

Topping

If you’ve read my post on stopping the bleeding, this is the crux of “topping”. You may have a variety of strategies for this but here’s the fundamentals.

Incoming Customer Defects

Ringfence enough capacity to address defects as soon as they come in. Make sure your burn rate matches your incoming rate. If you’re strapped, it’s your call whether you only cover high severity issues but for my money, I’d hit them all. A multi-year build-up of low severity issues makes products ugly, no pleasure for the users and a series of minor problems rapidly becomes a major burden and a big debt buildup.

Addressing every incoming defect doesn’t mean fixing every one. Whilst I generally recommend you do, when trying to dig yourself out of an oubliette the bigger issue is how to keep your goal achievable.

Be critical. The big, nasty bugs are usually pretty obvious but what about the rest?

    • Is it low severity and not important?
      • Is it quick & cheap to fix? – Just fix it.
      • If it’s not – Can you put a safety rail around it? Document it as a limitation or even ignore it?

Negotiate with your customers and make an explicit decision to fix now or never. Once decisions are made, communicated and agreed, close the defects in your backlog.

Getting these conversations happening immediately makes customers far happier than pretending they’ll just go away and never making a decision. (but not quite as happy as fixing their issues).

Incoming Internal Defects

The story here is the same. I’ve called it out independently as many companies and teams do.

Those incoming internal defects speak volumes about your approach to quality.

Get the discipline in place to fix them when you find them or be brutal and admit which ones will never be fixed but don’t pussyfoot around!

  • If you provide a service to other internal teams, treat them as customer defects.
  • If they’re raised by your own team, are they on new code or exposing existing issues?
    • On new code, fix them! – No excuses .
    • On existing code, the problems are already there. You need to decide if what you’ve done has made it more visible or harder to work with than before and make a judgement call. Fix now or never, resolve or close.

In the next article in this series I’ll cover debt prevention