Wednesday, September 23, 2009

Weinberg's (First Three) Laws of Consulting


Font: AndrewScript 1.6
Source: Gerald M. Weinberg, The Secrets of Consulting


I re-read Gerald Weinberg's book The Secrets of Consulting (Dorset House, 1985) once every year or two. The first time I read it, about a dozen years ago, half of it seemed obvious while the other half seemed counter-intuitive. But I discovered that I too often ignored its obvious advice (i.e. "common sense"), and that its counter-intuitive advice is spot on.

Weinberg spills so many secrets ("give away your best ideas" being one of them) that it seems unfortunate to mention only the first three (and their corollaries), but getting past these is key to understanding the rest. And yes, I highly recommend getting a copy of the book so that you can discover the rest of the secrets, even if you don't consider yourself a consultant. Substitute "problem solver" or "agile coach" for "consultant," and most of the book will apply equally well (except perhaps the parts about marketing and pricing).

I actually lost a potential new client because of my inattention to the first law, or more specifically to its corollary. After having a phone conversation about the client's interest in transitioning to XP (this was about 5 years ago, when people still uttered the term XP), I met with the leadership team at their offices. On the phone, the person looking to bring me in talked about some of the serious challenges they had. But when I arrived, I heard little about these serious problems, only some vague notions that they wanted to improve how they did things.

Never mind, I was too wrapped up in my grandiose scheme to solve all problems for them using XP. I mentioned the challenges I had heard about on the phone, and indicated that I'd be able to help them fix it all. "What makes you think we have such serious problems?" Oops!

What Weinberg points out is that it's very difficult for us to admit it when we have serious problems. I didn't get the gig, because were I to have waltzed in and solved many large problems, it would have been far too embarrassing for the people in that room. Since then, I've promised as much improvement as their pride is willing to admit--per Jerry, 10%. (Of course, there's nothing that says you can't deliver more, as long as you are cautious about who gets the credit--see rule #3). Just last week, I found the rule to be dearly applicable in my personal life.

As far as the second law is concerned, we all tend to follow comfortable patterns, and this is often the cause of the problem: Once you're in a rut, it can be hard to get out. "We've always done things this way, that's just the way it has to be." The trick for a consultant is to help someone get out of a rut--which requires a change in direction--without themselves starting to fall into the same rut. You don't want to stay in one place too long as a consultant.

Some people have found Weinberg's "secrets of consulting" to be nothing short of greedy and cynical. They suggest the third law is all about taking as much money as possible from the client on an hourly basis. But Weinberg points out that this notion of not getting paid by the solution hearkens back to the first law: A solution expensive enough to require a consultant requires a problem too big to admit. Is it cynical to work in a manner that meshes realistically with normal human behavior? I don't think so.

I hadn't looked at The Secrets of Consulting in about two years. That's evidence of the rut I was tracking in. I've recently been shoved out of my rut, and I am thankful that someone reminded me (with the utmost subtlety) to revisit the book. I'm looking forward to re-amplifying my impact!

Wednesday, September 9, 2009

Stopping the Bad Test Death Spiral





Fonts: Daniel, Daniel Black
Source (SCUMmy Cycle): Ben Rady, Rod Coffin of Improving Works from their Agile2009 presentation.
Source (Remedies): Tim Ottinger & Jeff Langr


The "SCUMmy Cycle" is all-too-common. A team with legacy (untested) code tries TDD hoping they will be able to continue making improvements. First efforts result in integration tests, perhaps because the code is tightly coupled and not cohesive. The team intends to someday replace them with proper unit tests. A team lacking essential understanding of the qualities of a good unit test will write integration tests unwittingly.

Months or years later the tests are abandoned, with a significant investment in their construction and maintenance having gone to waste. How does this happen?

Here's how the cycle generally plays out:
  • Only integration tests are written. One common cause: business logic is intertwined with UI or database code, perhaps as a reflection of examples found in framework and library tutorials.
  • More tests are added, until running them is slow/painful. Fifty to 100ms to interact with a database doesn't seem bad. But multiply that by a few hundred or thousand tests, and a even small test suite execution takes several minutes.
  • Tests are run less often because developers can't afford to run them. Developers will resist running ten-minute test suites more than a few times a day. Less-frequently-run tests are much harder to resolve when they fail. Large tests tend to be fragile and fail intermittently. They have runtime dependencies on external elements that are not controlled by the tests, and perhaps dependencies on side-effects other tests.
  • Tests are disabled because they are unreliable, obsolete from lack of maintenance, or simply too slow to tolerate.
  • Bugs become commonplace just as they were before the team started doing automated testing. Disabling too many tests lowers coverage and the remaining tests become ineffective.
  • Value of automated testing is questioned--"we're no better off than before!" And yet the team still wastes time writing and (sometimes) running tests.
  • Team quits testing in disgust, or managers mandate a stop to testing. The experiment is deemed an expensive failure. Teams are now free to return to the good old days of rapid coding and expensive manual testing. As W. Edwards Deming said, "Let's make toast the American way: I'll burn, and you scrape."
A sad progression, and it's real. Both of us (Tim and Jeff) have experiences confirming Rod and Ben's SCUMmy Test Progression. At each step along the progression it becomes harder to salvage the testing effort. Plenty of teams have started rough, but have recovered before reaching the bottom of the progression.

One possible lesson: it's cheaper to have no tests than to have bad tests. A better lesson: life is too short to settle for crummy tests.

The flip side of this card lists some therapeutic strategies for each downward step:
  • Only integration tests are written -> Learn unit testing. This also ties in with a better understanding of (and adherence to) the SRP and LoD. Consider hiring a short term coach to teach healthy habits in the team, or invest in better reading materials and the time to absorb the material. Attend a training session.
  • Overall suite time slows -> Break into "slow/fast" suites. Establish a time limit for the fast suite, and strive to keep the fast suite large and fast. Thousands of unit tests can easily run in under 10 seconds. Consider a tool like Infinitest to help keep tests running fast (but note that everything works better in a system that exhibits low coupling).
  • Tests are run less often -> Report test timeouts as build failures. The measures you institute will be arbitrary, but the key focus is on continually monitoring the health of your test suite. If the suite slows dramatically, developers will soon skimp on testing.
  • Tests are disabled -> Monitor coverage. New functionality should have coverage in the mid-to-high-90% range, and the rest of the system should exhibit stable or increasing coverage. System changes resulting in reductions in coverage should be rejected. Integration tests provide broad coverage, but you should either replace these with unit tests or elevate them to acceptance tests. You should otherwise delete disabled tests.
  • Bugs become commonplace -> Always write tests to "cover" a bug. These tests should always be written first, a la TDD. A defect is evidence of inadequate test coverage. Make sure you always track defects and understand the root cause of each and every one! Insist that these tests be fast tests.
  • Value of automated testing is questioned -> Commit to TDD, Acceptance Testing, Refactoring. Committing to TDD means learning how to do it properly--it is of low or negative value otherwise! Also note that many "regressions" are rooted in code duplication. Refactoring to eliminate duplication is critical for quality improvement. It is reasonable that a quality crisis causes a reduction in new features production.
  • Team quits testing in disgust -> Don't wait until it's too late! If a team's gotten to this point of admitting defeat, it's often too late--management won't normally tolerate a second attempt at what they think is the same thing.
In the adoption of unit testing, a few training sessions and a little time with a good coach can make all the difference in the world.

If you must self-coach, then ensure that team members don't view TDD as simply "management forcing programmers to test their code." Ensure that programmers understand the significant design and documentation benefits that TDD can deliver. Ensure they understand the scalability advantages of fast automated tests over manual testing.

A team that understands TDD and strives to attain the benefits it offers will avoid the Bad Test Death Spiral.

Tuesday, August 25, 2009

Test SCUM


Font is "Pen of Truth"

Source is Ben Rady and Rod Coffin of Improving Works, given in an agile presentation at Agile2009.

In sharp contrast to the FIRST principles of good unit tests, Rady and Coffin give us these properties of completely bad (scummy) unit tests.

  • Slow: We discussed now important speed is in unit tests. I find that when tests are more than 40 seconds, people have to decide to run them, rather than feeling free to run them immediately after every small step. Rady's Infinitest runs tests automatically and analyzes the tests to selectively exclude those which have no (discernable) transitive dependency on the system under test, just to eek out some extra speed. While it is preferable to run all the tests all the time, in many circumstances culling the unrelated tests will give back some speed.
    Tests are generally slow because thy provide insufficient insulation from the environment. They tend to spend a lot of time waiting on clocks, file systems, databases, web services, or the like. Slow tests are best rewritten with isolation from the environment.
    How fast is fast? I find that I can tolerate a usefully large battery of tests if each of them takes about .002 seconds. I can tolerate any number that starts with a dot and two zeroes. I might be able to tolerate a very few with only one zero immediately after the dot. More than that is "slow". It doesn't take many multi-second tests before developers feel reluctance to run them.
  • Confusing: We have emphasized that good tests isolate errors and their causes. A confusing test is one that fails to isolate a specific error. This may be because it has too many things going on, or because it is simply unreadable. It is preferable that the combination of the test class name, the test method name, and the assertion gives all the information a developer needs in order to correct a misstep. In a confusing test, those three items are not enough an the entire body of the test may not shed light on the failure mode. Confusing tests are best rewritten as smaller, more clear tests.
  • Unreliable: Tests should be repeatable: they should always fail the same way, or always pass for the same reasons. Tests that run only in isolation or on certain days or times of day are not reliable tests. One of the best ways to judge reliability is to run tests repeatedly. Note that overspecification often causes tests to fail in unexpected and non-useful ways.
  • Missing: The tests that you don't run provide you no benefit, and quite a bit of harm. Tests help you to design your production code, and also help you to tell if you are making decisions that break the system in unexpected ways. Not having the tests means that you just don't know. Maybe your design is iffy in ways you hadn't noticed. Maybe you've broken other code with your last line of code. Maybe the behavior you hand-verified last hour is no longer occurring as you expected it to. The tests you did not write are the ones that are really holding back your productivity.
While we could list other unwanted qualities of tests, these seem to describe the most painful sins.

Thursday, August 20, 2009

12 Principles for Agile Software Development


Font (once again): MechanicalPencil

The canonical source for these principles is the agile manifesto website.

These are the basic agile principles, abbreviated to fit onto a 3x5 card without requiring the reader to hold a magnifying glass. They are "sound bites" and not the whole story. Each of these principles can (or has) launched myriad blogs/articles, and indeed many of the other Agile in a Flash cards touch on these principles. We could easily build a distinct card for each, though that would inflate the size of our eventual card deck quite a lot.

It has long been Tim's perspective that Agile is about having a short reach so we are allowing that point of view to color our summary of agile principles.
  1. Satisfy the customer through early and continuous delivery--We shorten the distance between requirements gathering and customer feedback. The period is shorter because we plan less change at a time, and in return we get more opportunities to steer the software in a direction the customer appreciates. Notice that the principle actually says "continuous delivery", not just "quarterly" or "bimonthly." Early and continuous delivery is not about working faster, only about working sooner.

  2. Welcome changing requirements, even late in development--We shorten the distance between conceiving and implementing an important change. We don't have to wait for a redesign of the whole system, or for the next system to be built. This is not to say that no features will be delayed because feature requests are frequently reordered or even dropped. The agile difference is that such changes take effect sooner.

  3. Deliver working software frequently--We shorten the distance between the system-as-designed and the system-as-built. Both will evolve as we learn more about the system as it should be built. We also shorten the distance between planning and delivery, giving more opportunity to improve the efficiency and effectiveness of our work.

  4. Business people and developers work together daily--We shorten the distance between a question and its answer, both in time and space. Moving the customer to a different building, area, room, or even to a cubicle just around the corner dramatically reduces the number of questions we ask the customer. With collocation, the business and technology sides learn to better understand each other and to make more mutually-beneficial decisions.

  5. Build projects around motivated individuals--We shorten the distance between intent and action. The goal is to build an agile team of skilled professionals who care about all the business concerns including schedule and content, and who will work in a highly-engaged and result-oriented way. Such individuals need no babysitting and very little direction. Such a team will refused to be blocked, and will produce their best work at all times. Management does not have to spend time on motivational issues or "cat herding" so common to less-motivated teams.

  6. Convey information via face-to-face conversation--We shorten the distance between a question and its answer. Agile teams work in bullpens because it makes it much easier to ask questions and offer suggestions. Things that should be communicated get communicated, not forgotten, diluted, or otherwise insufficiently communicated. While there are many attempts to go agile without co-locating team members, we are not aware of any which have the kind of success which is typical in co-located teams.

  7. Working software is the primary measure of progress--We shorten the distance between thinking we're done and knowing we're done. The team should be judged by the product it produces, not by the rate of typing or number of degrees, or hours worked per month, or how quickly the members walk from the parking lot, or how quietly they work from their individual cubicles. A good team frequently produces quality software the customer wants. All other measures are subordinate or irrelevant.

  8. Maintain a constant pace indefinitely--We shorten the distance between the amount of unproductive time spent building software and a satisfying work day. This doesn't mean that management sets a large minimum hour limit for developers to endure months or years at a time. Excessive overtime cannot continue indefinitely without severely impacting quality. Instead, we choose a pace that allows us to go home tired and satisfied in the evening, and then return fresh and ready to rock in the morning. For normal people with families and bodily needs, that pace will not be 90 hours a week, and it probably won't even be 50 hours a week. We are never impossibly far from our life-sustaining relationships and activities.

  9. Give continuous attention to technical excellence--We shorten the distance between implementation and ideal. An agile developer is never more than a few minutes away from the last time all the tests passed. Collaborating classes are not at the opposite ends of long chains of contains/references/inherits relationships (e.g. "train wrecks"). Developers need not wait to clean up redundant or confusing code. If working code is the measure of agility, then excellent code must be defined as code that accepts changes gracefully. An agile team takes steps to ensure that code gets better with each iteration.

  10. Simplify: maximize the amount of work not done--We shorten the distance between comprehension and completion. We eschew things that don't matter. If we're less encumbered by unhelpful tasks and unwanted features, we've shortened the reach to useful work. We also attempt to simplify code (reducing the amount of reverse-engineering other programmers must do). Agile programmers tend to follow the rules of simple design.

  11. Teams self-organize--We shorten the distance between need and action. We don't wait around to be told who does what. We do what needs to be done, not waiting for direction or supervision. We attack problems with fervor, mitigating risks and clearing obstacles.

  12. Teams retrospect and tune their behaviors--We shorten the distance between introspection and adaptation. Improvement is never far away. Each iteration, we explicitly find ways to improve process simplicity, code quality, technical excellence, and predictability of results. We analyze problems and obstacles, and look for root causes and their solutions. We actively plan to use better techniques, tools, and process flows. We act on the plan in the subsequent iteration, without delay.

These principles are fairly simple in concept, but are profoundly deep in practice. If you are transitioning to an Agile work style or are looking for ways to improve your current Agile practice, we suggest you begin again with the principles espoused here.

Tuesday, July 28, 2009

Essential Unit Test Cards

What are the essential unit test cards? Some of you have asked for these to be assembled into one place, so here we are:
With this deck of cards, you have enough information to understand how to go about TDD, how to work around some problems, and why you should bother. Throw in the wikipedia article and its links (, a nice xUnit framework for your language, and you should be able to competently carry out TDD on your current project. If not, let us know what TDD cards you really need, but don't have.

Friday, July 24, 2009

Plan-Do-Check-Act


Font: Daniel Black

Thanks to Igor Czechowski for suggesting this card.

At the core of agile is short cycles of Plan-Do-Check-Act (PDCA). These steps are also what it means to be scientific in approach, at least per the definition of science that says you are following the scientific method: hypothesize, experiment, evaluate. Those who say agile isn't disciplined have not made this connection.


Plan-Do-Check-Act is echoed in agile practices, particularly TDD. The Plan step is about "making the expected output the focus," per Wikipedia. Writing a test that first fails captures your plan. After observing test failure, Do means you write enough code to make the test pass, and Check tells you to verify the actual results against the expected output. If there are differences you must Act to determine their cause and correct your implementation (or sometimes your expectations). In any case, you must also Act by observing the changes to the environment--the rest of the system--and "determine where to apply changes that will include improvement," which can mean some doing some incremental refactoring.


The iterative-incremental development core of agile also follows the cycle:


  • Plan - iteration planning/definition of acceptance tests

  • Do - day-to-day iteration execution

  • Check - verification of results using acceptance tests

  • Act - retrospectives and subsequent planning



As with many of the best modern ideas for quality control, PDCA in part comes from Dr. W. Edwards Deming. While Deming credited Walter Shewhart for the original concept of PDCA, Deming gets credit for popularizing the cycle.

Wednesday, July 22, 2009

Naming Fail or Comment Fail?

Names changed to protect the innocent:

/// Adds Sessions which fit in specified date-time range
private void ReadSessions() {