10 Signs that Your Team Isn’t Really Agile

[UPDATE – This post was recently translated by Choepidiui (I hope I got the name right) into Korean. For the Korean version of this post, please go to his site]

With all the hype in the software industry about Agile, Scrum and so on, it is no surprise that many companies hear or read about the virtues of these methods, perhaps at a conference or in a technical white paper, and think “we need this here”. Unfortunately, some organizations are not as ready to make the mental shift required to embrace the agile way of doing things…

Below is a (by no means conclusive) list of signs that your team waded in toe-deep, rather than going the whole nine yards:

You might not be truly agile if…

1. Your team is not responsible for the entire story

Perhaps the most important aspect of an agile team is that it is cross functional. This means that the team, as a whole, have all the skills required to deliver a valuable product increment. If a team has only client developers, then all server-side tasks are probably relegated to a different team. In this case, the team is not handling a story from end to end; when they complete their work, no value has been added to the product – not in the eyes of the customer! Teams that work like this resemble a factory where the product sits on the conveyor belt and different layers are added to it by different teams. At no moment till the last team does its thing is the feature (or product) done.

It is possible to have a successful development process without cross-functional (feature) teams, but it simply isn’t agile.

2. Testing is done by another team

Another equally important quality of an agile team is the ability to deliver a working product increment. If the developers call a feature that has merely been coded and not tested “done”, then there is a serious flaw with their definition of done. This is often another example of not being cross-functional: QA is simply another team. In order for a team’s work to be considered done, it should be tested and integrated and ready to use.

3. You are not INVESTing in your user stories

INVEST, is a mnemonic acronym coined by Bill Wake that describes the values of a good user story: Independent of other user stories, Negotiable scope up to the sprint in which they’re developed, Valuable to the end user or customer, Estimable by the development team, Sized appropriately so that the team can complete a few of them in one sprint, and Testable so that the team can prove that they have successfully completed the requirements.

Only if the product owner INVESTs in the stories, will he be able to order them by their value to their customer, and be able to promise that when each is complete, the customer will receive a valuable increment to the product. Likewise, the team will be able to deliver these increments rapidly, and with confidence in their quality.

4. Tasks are assigned to team members by a manager

In a truly agile team, each member can pick which tasks he or she will work on next, as long as it pertains to the next most valuable user story. Traditionally, project managers or team leaders would assign tasks to team members, often months in advance. Even though this is done for the sake of optimizing a project schedule, it is a wasteful process that can’t possibly take into account how the entire project might change over time, nor what the team members’ skills and desires might be at the time.

A team member may want to focus on improving his skills, or try to learn to do something outside his comfort zone. A responsible, self-managing team will find a way to make sure the tasks get done as soon as needed and in line with the reality of the project as it is at the present. The best the manager can truly hope for is to get out of the way. Besides, he has more important things to do.

The only time a project manager should expend the effort of allocating resources is when a task requires a resource that the team doesn’t have. Those should be few and far between. If this is a recurring issue, it is a sign that the team isn’t cross-functional enough (see the first point, above).

5. Your team is told how much work to commit to

If a PM gives the team a certain set of resources (members), a deadline (release or sprint), and then tells them how much work they should commit to (or vetoes their commitment), then the project manager is guilty of attempting to break the iron triangle. A team should be able to commit to as much work per iteration as they believe they can (and should base their estimates on past experience).

If this isn’t the case, then there is nothing agile about the plan; the plan was set in advance, etched in stone, and you aren’t willing to renegotiate it, even at the implicit expense of quality.

For a team to be truly agile, it must be accepted that the plan might be delivered with less than all of the stories originally planned (and it should be the least valuable ones that get booted).

6. You are reporting rather than discussing your progress

A subtle and insidious sign that you aren’t really agile is that you report your progress to the project manager scrum master, not to the team, at the daily stand up meeting. The meeting is there so that the (entire) team will have a sense of what each other is doing, what they are stuck on, and what they are planning to do.

Despite the seemingly managerial nature of the three questions asked (“what did you do since then last meeting?”, “what are you planning on doing till the next one?”, “what might block your progress?”) , the questions are not there for the manager to keep tabs on the team, but to elicit another team member’s thoughts on the matter (“can I help?”, “does this affect my tasks?”, etc.).

Each team member should be addressing the rest of the team. The PM should be there to listen, and perhaps answer questions; he should not become the focus of the meeting.

7. You are not focusing on completing the most important user story

Sometimes, a team may divide their work into stories and break them down into tasks, but instead of swarming on the topmost story and divide the tasks among members, the stories are divided. This has two un-agile consequences:

First, at a given time, all of the stories may be partially completed (regardless of value), instead of part of the stories (based on value), totally complete. This transforms the team and the iteration plan into a waterfall-ish plan, rather than an agile one, as its success is based on the premise (hope) that everything will be completed on time, otherwise, nothing is.

Second problem is that each member’s work has less impact and import to his team members. It is not their story he’s talking about, after all. The other members have less of an incentive to listen and help. The daily meeting becomes a mere progress report that can easily be replaced with a query to the chosen ALM tool.

For a team to be agile, they have to be geared towards working on the same problem, and put all their effort into cranking out complete features, as quickly as possible.

8. You changed to agile last year, and haven’t changed a thing since

Here’s a tricky one – you think you nailed it; you may have brought in an expert way back then, and we worked out a plan, and it seems to work, and now it’s etched in stone and  nobody can change it. Well guess what – you’re missing on an important part of being agile: Actually being agile! Reality changes, new ideas and new influences come up all the time. There’s always something that could be done better.

An agile team holds retrospectives on a regular basis, where they put their heads together to think of what they did right since the last meeting, what they could do better in the next iteration, and what visible actions need to be taken to improve.

These visible actions most often manifest as a change to the work process.

Note: If you are using an IT-based ALM tool to manage your work process (e.g. TFS, Greenhopper, etc., Version One) you should take care to account for the impact of the change on the tool.

Time to Publish

Sometimes there are unforeseeable problems that mean you reach the deadline, and you haven’t completed all of your planned work. If you storm your stories and make sure you deliver one complete story at a time, ordered by priority, you will likely have a good enough product (yes I know I made this point before, but it’s worth repeating…)

So it’s time to post. I know I promised 10 signs in the title, but it turns out that I can’t. At least I came through with the most important ones, fully ready on time, no?

Well, if you don’t feel that way, and you think it is more important to deliver everything, than it is to meet a deadline, then here’s sign #9.

9. You are not ready to release on time with an incomplete scope

If you can’t organize your work in such a way that you’re ready to deliver the most important features, those you’ve completed, at any given moment (especially at the deadline), then your plan isn’t agile. You are likely building your product in layers, like a house, rather than in vertical slices, of product value increment.

An agile product is built one user story (or value increment, or minimal marketable feature – doesn’t matter how you call it) at a time. For more on it, read my post on how to plan agile releases.

Here’s another one:

You can always release the remaining features at a later date, with a minor release increment…

10. You are not getting customer feedback every sprint

At the end of every sprint, an agile team demonstrates the latest increment to the product. The audience may include any and all stakeholders in the project, it definitely includes the product owner / project manager and should, when relevant, include the customer. Some teams use this as some formal milestone to show their progress, and continue with the (original) plan for the next sprint – regardless of the results! This is not agile.

A truly agile team will leverage the demo to elicit comments from the stakeholders about the recent development, to make sure that they are on track, and that if the requirements or environment changed during the last sprint, these changes will be reflected in the product backlog and potentially in the upcoming sprint backlog!

Remember, and agile team embraces change, rather than avoiding it.

Summary

There. That’s 10 signs. I hope you found them enjoyable as well as educating.

So do you have any more signs that should be added to this list? Please add them in the comments.

Assaf.

[EDIT]

11. You’re not agile if you can’t deal with a change in the original scope.

Now, I know I said there’d be (only) 10 signs, but based on early, prerelease feedback, I was asked to add another one. I showed them to a friend of mine before posting, and he liked what he saw. In fact, he liked the idea so much, that he suggested another one that I might add. After the release however, he suggested I change the wording. I hope you like this one better..

Technorati Tags: Agile,Definition of Done,Scrum,User Story

How to Use Agile Estimation in Scrum Projects

Like it or not, estimations are a big part of professional and commercial software development. Estimations are used in most projects regardless of methodology: Waterfall or Scrum, traditional or agile, every stakeholder needs to know the numbers. Projects succeed or fail as a result of these. Unfortunately, humans, as a rule, tend to suck at estimating.

This post will compare and contrast the different estimation techniques and applications used by both agile and non-agile methodologies, and explain how to use them (and not misuse them), particularly in a Scrum project.

What is Wrong with how We Estimate?

Traditional project plans involve using calendric estimates in order to synchronize the development efforts of the team(s) by placing the work on a time line (usually, using a Gantt chart). This means that for every part of the solution, the developers must predict the when it will be ready (i.e. the delivery date). This means they need to know when they will start, how much time it will take to deliver the work, and how much time will be “wasted” on impediments (both foreseeable and unforeseeable). While knowing this makes the project planners’ work easier, obtaining this knowledge is extremely difficult; Estimating the development effort is difficult enough, but predicting the total amount of time that will be spent not developing is near impossible.

What’s worse, is that contrary to popular belief, the Law of Large Numbers does not apply to project plans! Due to the nature of dependencies, a single late dependency is enough to push the delivery date of a dependent component. On the other hand, in order for a component to be delivered early, it is necessary that all dependencies will be completed early. In short, lateness aggregates, while earliness does not.

A side effect of this is that the more complex the Gantt based project is, the more lateness is likely to be accumulated, as the project advances, and the further we are in the project, the more we run the risk of being late.

Of course, a late project means that the software is delivered at a higher cost, with less features, and / or simply later than expected and agreed. This means that a late project often becomes a failed project.

Clearly, a different method of doing things is necessary; Agile methodologists came up with different estimation techniques to reduce the chances and ramifications of failure.

Agile Estimations Are Easier to Make

The three most common agile estimations are T-Shirt Sizes, Ideal Time, and Story Points:

• T-Shirt Size estimations are coarse grained separation of requirements into buckets of small, medium, large, or very-large efforts. This estimate is of course extremely easy to make intuitively, and of course insufficient as a basis for project planning due to its low resolution, but is often sufficient for the purpose of pricing single features (example scenario might be when required to give a customer a cost estimate for some custom feature in the system).
• Ideal Time estimates are similar to calendric estimates in that they involve high resolution predictions of the effort involved in developing a feature. The difference is that ideal estimates are made while ignoring all surprises and interferences! The question that ideal estimates answer is “how much time will it take to develop a solution, assuming you work on nothing else, and nothing else disturbs you”. Taking the unknowable impediment factor out of the equation improves the accuracy of the estimates, but you can’t simply substitute ideal time for calendric time because the unknown impediments still do exist, and the fact remains that humans aren’t good at making absolute estimates, with no point of reference. In Scrum, Ideal Hours are often used to estimate the effort of completing tasks, which should be short, simple and straightforward.
• Story Points are a radically different method of estimating development effort. With story points you do not go out and say how much work something is, in and of itself, but rather state how the effort to develop one component compares to the effort of developing another. These estimates are much easier to make, and surprisingly accurate because we are much better at comparing things than estimating them. Of course, comparisons and relationships have no unit of measure, and thus can’t be used to establish a timeline. At least not in the normal sense. In Scrum, Story Points are usually used to estimate the effort of completing user stories (hence the name).

Agile Estimation Techniques Make Better Plans

While agile estimation techniques tend to end up more accurate than calendric estimates, the estimations are still guesses, and guesses still mean risk. Agile teams try to reduce this risk by reducing the amount of guesswork involved in the project plan.

Classic project plans involve estimating the time it will take to deliver each component, and add up all the estimates to create one big guess-of-a-plan. While agile project plans involve estimating the work on each component as well, that is where the similarity ends.

The agile project plan is not based on the prediction of work effort, but rather on empirical evidence! Only the team’s first iteration (ever) is planned based on a prediction. The rest are based on the measured evidence of previous iterations (or sprints, as they are often called in Scrum-shops). The team estimates that it will successfully complete as much work in the next iteration as it did in the previous iteration(s).

For example, if a team successfully completed 120 ideal hours worth of work (that is, the amount of work they did added up to what they estimated as 120 ideal hours), then they will estimate that they will do the same in the next iteration. This technique works the same with story points: A team that can complete an average of 50 story points in an iteration is likely to repeat that success in the next one. A team’s velocity, or cadence can then be measured in ideal hours per iteration or story points per sprint.

What about interruptions? Well here’s the beauty of the technique: You can consistently account for the predictable ones (e.g. vacations, repeat meetings, scheduled events) and factor those out, and you can consistently ignore the unplanned ones, as they are likely to be more or less an equal part of every iteration of the team.

Where’s the Difference?

The difference between predictive plans (classic, waterfall-ish, Gantt based) and empirical plans (Agile, Scrum) are:

1. Predictive plans are based on more estimation (i.e. guesses, i.e. risk) than empirical ones
2. Empirical plans have an increasingly sound statistical ground as the project progresses
3. Predictive plans have an increasing chance of running late, as the project progresses
4. With predictive plans the unknown factors aggregate, with empirical plans they cancel each other out.

Finally, as stated in the previous post, agile plans, being based on stories that are designed to be discrete units of business-value, with as little interdependencies as possible, agile plans further mitigate the risk of estimation failure by causing the ramification to be failure to deliver on time only the least valuable features!

In Conclusion

To me, the agile choice is a no brainer. Agile plans are simply safer to execute, the chance of failure is lesser, and the result is less harmful. I would even go as far as to say that companies promising to deliver a non-trivial project without using an agile plan of some sorts are being less than honest – with themselves as well as the customer.

Moreover, I think it is high time that customers demand their contractors to use agile methods in order to win contracts.

Technorati Tags: Agile,Estimation,Scrum,Release Planning,Sprint Planning,Story Points,Ideal Hours

Demystifying Agile: How to Plan Releases with Scrum

The agile release process might sometimes seem like voodoo (or even dark voodoo) to some managers and developers, particularly those more accustomed to the traditional way of planning processes used in waterfall projects. This post will explain the inherent problems with waterfall projects, how agile methodologies such as Scrum overcome these problems, and of course, the reasons that the agile release planning method works.

You Can’t Control Everything

The PMBOK call it the project management triangle; the agile community call it the Iron Triangle. Regardless of the name, it is a real and hard constraint: Of the three aspects of the project – scope, resources (or cost), and time you may pick and control any two. The third cannot be controlled without harming the quality, and is calculated (roughly) by the following formula:

This means that if you have a project where the budget is fixed, and there is a hard deadline (i.e. release date), then you cannot control the scope that will be delivered by the team by the time of the release.

Moreover, Brook’s Law, states that adding people to a late (i.e. already started) project will only make it later. According to this, since the cost of a software project is mostly the cost of the team members, the resources must remain fixed for the project (or release).

Nevertheless, traditional project managers seem to try to define the entire scope of a project, define the releases and milestones (i.e. the time), with a fixed preset budget (i.e. cost).

It is simply doomed to fail. According to the Standish Group and the Chaos Report, most projects (68 percent) do.

Why do Projects Fail?

According to Martin Fowler, it is not the projects that fail, but rather the estimates that fail; it is our attempt to calculate how much time it will take to deliver a certain scope with a certain amount of resources.

I would argue, that the failure to estimate is the reason that projects fail. We really don’t know how to estimate. Projects fail because they rely too heavily on the estimates.

How do Agile Methods Reconcile with the Iron Triangle?

Given values such as courage and honesty, it is no surprise that agile methodologists simply acknowledge that estimation is not a good basis for a release plan, and search for alternatives.

Given the Iron Triangle, Brook’s Law, and the fact that most customers demand a hard release date, an agile PM accepts that he cannot control the scope that will be delivered; that is, while the PM may make guesses (i.e. estimates) as to the content that will be delivered on the deadline, he cannot be sure that every last task will be completed.

What he can promise, and make certain of, is that he will deliver the best product possible on the release date, with the rest of the desired features in consecutive releases.

How do Agile Methods Deliver the Best Product on Time?

By slicing the entire scope into vertical slices, small increments in valuable functionality (often called user stories), the agile PM now has a stack of user stories to be released, or a product backlog. By defining the stories in such a way that they have as few interdependencies as possible, the PM may order them as he desires. The PM will of course, choose to order them by business value to the customer.

The development team, in turn, will swarm on each story, by order of value (priority), and focus on completely delivering one story at a time (completely means coding, testing, integrating and anything else required).

In this way, at any given moment, including the release date, the team has a product that is shippable and is the most valuable product they could possibly develop.

Is the Best Product Possible Good Enough?

While the best product might not be everything that was envisioned, because again – that is simply not possible: not with waterfall, not with agile, not anyway – the “Best Product” will have the capabilities most valued by the customer.

The findings of the Standish Group show that only 20% of the features in any given product are frequently used, while 64% are rarely or never used. Therefore, statistically speaking, even if you only complete 36% of your scope, you may still have a good enough product!

Of course, assuming that you aren’t slacking, and the project’s deadline isn’t insanely short, it is more likely that you will complete a significantly larger portion of your scope. It is even possible that you will have a “good enough” product that you can ship even before the deadline! There is not a single customer that will say no to reducing time to market!

So I’d say, yes – the Best Product is good enough.

And that’s how it’s done. I hope

How about your products? Do you work this way? Are your experiences similar? Share!

Thanks,

Assaf.

Technorati Tags: Agile,Estimation,Scrum,User Story,Release Planning,Sprint Planning

Demystifying Agile

Understanding the mechanics of Scrum is easy; otherwise there’s no way they could be taught in 16 hours, in a Certified Scrum Master class. Understanding why the mechanics work is a different thing altogether. In this series of posts, I will attempt to explain how and why they work the way they do; I firmly believe that attempting to use the mechanics of scrum without understanding the Agile spirit is a recipe for failure. I hope you enjoy the series.

Table of Contents:

1. Demystifying Agile: How to Plan Releases with Scrum
2. How to Use Agile Estimation in Scrum Projects
3. Proving Pair Programming: How and Why it Works
4. How to Manage a Self Managing Team
5. Agile Contracts: Unveiling the Trick to Happy Customers
6. Agile Tips & Tricks: How to Solve Real Issues with Scrum

Bookmark this page! More posts to come…

Technorati Tags: Agile,Scrum

A Software Developer’s New Year’s Resolution

Or: 5 Things You Can Do Today to Improve Your Software Product

New Year’s eve is around the corner. It is the end of this year, and there’s a whole new year full of potential to be better, just waiting to begin. So how can you make it better? If you, like me, are a professional developer, then you can improve your life (and your boss’s and your team’s) by reducing software delivery related stress. Here are 5 things you can do, effective immediately, to make your product better:

1. Make a Version Management Plan

If your version control system is a mess, the first thing you should do is straighten it out. If you are not using one, then you should begin doing so immediately. There really is no excuse not to do so. For starters, there are plenty of high quality tools out there that are open source and free (git, mercurial, and subversion are the most common ones), as well as other commercial tools (I happen to use and consult on the use of Microsoft’s TFS). Either download and start using a free one, or get one that offers a trial period.

If you are using a VCS, but it’s a mess, and you find yourself mired deeply in merge-hell every time you want to deliver your software (internally or externally; it doesn’t matter), then you should straighten it out. Unfortunately, if you have a considerably sized source repository, this may seem as an impossible endeavor. Here’s one way to alleviate at least some of the pains of software delivery, in a few easy steps:

1. Create a new root-level folder named sources. This folder will contain your new source code repository.
2. Create a branch from your current repository, and call it main (e.g. /sources/main). This will represent your latest and greatest version, and should be kept as stable as possible, at any moment. No development will be done on it; you will only merge completed changes into it.
3. Create a branch from main, named dev (e.g. /sources/dev). This branch will be the branch that developers work on to create new features, checking code in and out from there. If there are multiple independent teams, you may have multiple dev branches.
4. Create a releases folder, which will contain release branches from main. Every time you wish to release your software (internally or externally), create a release branch from main (e.g. /sources/releases/1.2).

This is just one possible branching plan. It works particularly well for agile development, where effort is made towards developing as many features as possible before a release, merging them into main when ever they are done, and branching when the iteration is over. Note the following division of work:

• New features are developed only in dev. They are merged back into main when completed.
• Fixes are developed on release branches and reverse-integrated into main, and then back to dev, so that they won’t get lost.

This structure allows you to develop new software and stabilize a release at the same time without one effort polluting another. It is also a step towards being able to release a new version anytime.

If your development and release mechanism is well established, but not suited to fit this branch plan, make one that does work. Just make sure to be able to support feature and fix separation as well as the ability release anytime you need.

2. Automate Your Build

Even if all you do is copy sources from the repository to some drop folder, you have some sort of a build process. Automate it. Even just a part of it. Even just the compilation phase. Every step you let a computer do rather than yourself, is one less step to worry about. If you aren’t already using an automated build tool, you should start now. There are many open source tools as well as commercial ones. Most are powerful enough to suit your needs. Remember – If you can run it from command line, you can automate it as well.

Every time you run the build, you will not only create a deployment package of your system, but you will get a good indication about the health of your product (if the product doesn’t build, you will want to know sooner rather than later). Additionally, you will have the start of a platform for testing the system.

For a synergetic benefit with your versioning plan, schedule the following automated builds:

• Build the software every time you check in changes to your code (on dev or a release branch); most build and VCS tools support this – it is called continuous integration.
• Build the software every time you wish to merge dev to main. It is even better if you require a successful build as a prerequisite for the merge. This is called a gated check-in in many tools.
• Schedule a nightly build on main. This will let you know what the state of your system is. Fix any problems here first. Keeping a healthy build will allow you to deliver software at the drop of a hat. Amaze your PM!

3. Add a Health Report

Even a simple email message to the team in case a build fails will greatly improve your ability to fix problems with your software. Shorter feedback cycles means that you can fix problems when their causes are still fresh in your mind! Let your build system email you if it fails. Almost every system supports it. Conversely, you may wish to post successful build reports to some company wiki. Let everyone know of your successes.

4. Add an Automated Test

While the benefits of TDD as a design mechanism are far greater than just having a suite of tests, we should not belittle the benefit of an automated regression test. Even a simple record & replay automated smoke test, with a black-box test tool will greatly improve your system. Start with a single test that runs through as many parts of your system as you can easily manage. (Note – this might mean you need to add a deployment action to your automated build). Report if it fails. Run it every time you build. The more tests you add, the greater confidence you’ll have in your build system! Maintain your tests; fix any tests that fail due to legitimate changes and remove those that are no longer relevant. You don’t want your system to cry wolf!

5. No Broken Windows!

The most important thing you can do is to make a new year’s resolution that you will not suffer any problem with your software delivery lifecycle to remain unfixed! Once you fall off the wagon, your system will start to decay back to uncontrollable chaos. Think of maintaining your ALM like brushing your teeth. You may not like it but you do it every day (more than once), or your teeth will rot out until ultimately you won’t be able to eat!

In conclusion,

My new year’s resolution is to vigilantly keep my teams’ products “on the wagon”.What is yours?

Happy Holidays, and Happy New Year!

See you all next year,

Assaf.

Technorati Tags: Agile,Build,TDD,Test,Report,Version Control

How to Measure Technical Debt

Or: An Executive’s Guide to the Cost of Software Architecture Shortcuts

In my experience, in any software project of sufficient complexity, it is necessary to cut corners in the software architecture. These shortcuts are decision that you make now so that you will be able to release your next version of the software that much earlier; these shortcuts are the result of not having enough time to do things “right”.

This is called your project’s Technical Debt.

Like financial debt, which is the metaphor used to explain it, technical debt happens when you “buy” more software features than you have resources (developers and time) for. Like financial debt, it accrues interest over time. And like financial debt, if you don’t pay it back, you may eventually get foreclosed and go bankrupt. That last part is not a metaphor. Your software project simply ends up costing more to maintain than the value you derive from it, and either the project or the company gets shut down, or both.

There are essentially two ways to deal with debt (technical, like financial):

1. You pay it all at once – This means that you do not “withdraw” any more features, until your debt has been fully paid. It has the benefit of being able to make a fresh start. It has the disadvantage of risking “starvation” while you try to pay the “bank”.
2. You pay it in installments – This means that you pay off your debt, a small part at a time, still “withdrawing” features, but less than you normally would, cutting down to essentials, for as long as you are still paying off the debt. It takes longer to finish, but you can still “eat” while paying.

Of course there’s the third option of continuing to withdraw as before, until you go broke, or luckily win the ‘lottery” (investment, buy-out, etc.)

There is no one clear way to deal with debt (financial or technical). It will depend on the situation, and the players. And most of all it will depend on the amount of debt.

Quantifying the Debt

With financial debt, it is easy to determine how much you owe. There’s the amount of money you borrowed, and the interest rate. Both are usually well known, and it is just a matter of keeping track of it, to make sure you can withstand it.

With technical debt, you still have the amount you borrowed, and the interest rate, but you usually don’t know the numbers.

Let’s start with figuring out the derived value of taking the loan. Whenever you demand that a feature or set of features be completed faster than it would normally take if the team were to maintain an appropriate quality level, you are “borrowing” from the architecture. Figure out how much time you saved, and multiply it by the hourly cost of the developers. That is the amount of money you borrowed from the architecture. Figure out what the reduction in the Time to Market will earn you, and that is the derived value of the loan.

The interest rate is not so easily calculated a-priori, but it can be estimated (with about as much accuracy as the development cost estimates your team makes – which may be good or bad; depends on your experience):

1. Map out the areas impacted by the shortcut
2. Estimate how much it would cost (developers x time) to develop a feature in the impacted areas, before the shortcut(s)
3. Now, estimate the cost to develop the same feature after introducing the technical debt

The difference in the cost is the interest you are paying. Keep track of the interest as it will change with every change you make to the system. A good practice is to calculate the interest every iteration or sprint. You should consider doing this as part of the sprint planning. This will have the added benefit of giving the product owner the opportunity to pay off some of the debt.

Note that like financial debt, the interest grows over time. The rate varies, and it is difficult to guess what it will be, except by projecting based on past experience. As you begin to accumulate this data, you will be able to make educated decisions on when you can afford to go into technical debt, and when you should avoid it. You should reassess your technical debt’s interest rate every sprint planning.

Armed with this knowledge, developers should now be able to collaborate with management in order to decide how to develop and whether or not it is okay to cut a corner on that next feature.

Finally, remember: Your architecture is a cold blooded loan shark, who will just as soon take your installments, as he will bust your project’s kneecaps over a missed payment.

What do you think? Do you have a preferred method of calculating / estimating technical debt, or a way to handle it?

Please share!

Technorati Tags: Agile,Estimation,Scrum,Sprint Planning,Technical Debt

10 Reasons to Avoid Test Driven Development

Test Driven Development (TDD), and all of its derivatives (BDD, ATDD) are, in my opinion great methods to drive a team’s development efforts, and raise the quality of the product. But TDD is not a silver bullet. It doesn’t fit every project. The following post lists the top ten reasons not to write automated tests for your code.

 

If one or more of these conditions apply to you, you should consider forgoing TDD, and in fact any agile techniques, as they will be a waste of effort:

10. There is no client

Sometimes you are developing a product that will not be used by anyone. In this case, any effort expended on raising the quality is a complete waste. Nobody will care.

9. The client is an avid tester

Some people love nothing more than to beta-test new software. The joy of finding new bugs and trying to figure out what went wrong is what they live for. Others are scientists at heart, and love trying to go over stack traces, in order to reverse-engineer the code. If your client happens to be one of those, then writing automated tests will take all the fun out of using your software. Don’t do it!

8. The project is short, simple and straight-forward

If your team can complete the project in a short period of time (no more than a few weeks), and will never, ever have to reopen it for maintenance, then the benefits of maintainability, reusability and extensibility will be lost on you. Spending time and effort on these values is wasteful.

7. Your architecture is perfect

If there is no way to improve your architecture, then there is no need for it to be extensible. TDD, by the nature of its incremental development flow, forces the architecture to be extensible, simply by making you extend it as you go, and this, like lipstick on a pig, is something you just don’t need.

6. Your documentation is perfect

You never miss an API, and any change you make to your software gets documented instantaneously. The tests you create with TDD serve as a form of documentation, an example of how to use the API. Properly named and written tests actually explain the context of the test, so it is easy to find the test that shows you what you need to understand. Your documentation is so complete, that writing tests are a clear violation of the DRY principle, so you should clearly avoid tests.

5. Your team never changes and all members’ memories are perfect

The collective memory never forgets a single line of code it wrote, nor what the context was when writing it. You therefore, do not need the tests to remind you what the code does, why it does it, or how to use it. This also means that your team members never leave, nor are any new members recruited, because if this were to happen, you’d lose memories, or have members who don’t remember the code (having not been there when it was written). If this is the case, don’t bother with tests; they will just interfere with your incredible velocity.

4. “Done” means the code is checked in

Many teams have a definition of done (DoD) that means that the feature is “done” when it is in a state that the end user can receive and run (coded, tested, deployed, documented, etc.). Many others however, your team included, prefer a simpler and more easily achieved definition that accepts “checked in” as “done”. For you it is sufficient that the developer declared that he or she completed his part, and anything else is someone else’s responsibility. If you don’t need the code to be tested for the product owner / manager / user to accept it, then you are better served moving on to the next feature as soon as you can, instead of dragging on your relationship with this feature.

3. You’re paid to code, not test

Ignoring the fact that unit tests are code (sophistry), testing is what we have testers for. Perhaps your team's testers are fast enough that they can run tests on your code and give you feedback within mere moments, pinpointing the areas where you broke the code, so you can fix it while the changes are fresh in your mind, as well as a complete regression suite on the product, in case you broke something in a different component every night (they don’t mind working nights; they love the peaceful quiet). Good for you, cherish those testers, and make sure they have enough work so they won’t get bored and move on to a more challenging company.

2. Debugging doesn’t count, and testing takes too long

Like with any competitive company, your team must deliver on time, which means they must make estimates on the time it will take to deliver. Since your DoD doesn’t include testing, and you probably can’t guess how long it will take to debug the feature, what with all the cycling back and forth from development to QA, you estimate how long it will take to code it. If you want to meet your commitment, you can’t be adding a 20% overhead to your delivery time or you’ll miss the deadline. Worse, if you add 20% to your estimates, your manager might call you out on padding the estimates, which is his job. If that happens, who knows what might happen? Better play it safe.

1. It’s just a theory

Like Evolution (and Gravity), it’s just a theory. Even if all of the above reasons weren’t valid, nobody has ever successfully proven that this product could be completed faster and with better quality using new-age development methodologies like TDD. It’s just a matter of opinion.

Test yourself

Now, to test whether or not you should use test driven development, go over the above list. Count how many reasons apply to you. If you scored ten points, don’t use TDD. In fact, if you scored more than one (reason #8 might actually be legitimate), don’t write any code at all. Perhaps you’d be better served choosing a career that has fewer unknowns and moving parts. Perhaps paving roads?

Disclaimer: This post was written… Aw, just figure it out yourself!

Technorati Tags: Agile,Scrum,TDD,Estimation,Unit Tests,Definition of Done