Last week I briefed an IBM customer on some of our recent thoughts on the role of estimation in business analytics. I feel the briefing was not entirely successful. The customer asked about a use of estimation I had not considered previously My first reaction is that the approach desired by the customer was 'not possible'. I then realized it might work in some cases, but I was emotionally opposed to the idea. Then I realized I should not let my emotions interfere and think through the question and its implications. Hence this blog:
In Agile projects or in maintenance organizations, workers are assigned 'work items'. Often workers are asked to estimate the time it will take to complete the work item. Asking an employee to commit to a time-to-complete is both reasonable and unreasonable. Team leads and managers need to have some idea when the current work will be done to plan resource assignments, manage content, make commitments and the like. The management also wants to identify the more reliable, productive workers. After all, development teams are meritocracies. It is right that the more productive employees are identified and rewarded. So we need a way for employees to make reasonable estimates while providing a way for (cliche aler!) the cream to rise. It is unreasonable in that the worker is asked to guess and, in fact, commit to a time to complete. In some cases, the worker may be confident in the estimate. In some cases, there will be less confidence for a variety of good reasons: The task may have dependencies, the solution to fixing a bug report may not be apparent and so on. So asking to commit to a fixed time is unreasonable and measuring the worker against these commitments is oppressive. Under these circumstances, the intelligent worker will pad the estimate so to insure that the commitment is meant. This unintended consequence of asking for the duration is longer than needed estimates and, since people work to the commitments, lower productivity.
In the Agile Planning feature shipped in Rational Team Concert (RTC), we provided means to somewhat mitigate this phenomenon. RTC provides the mechanism for letting the worker enter the best case, likely, and worse case for the time to complete the task. This way the worker can enter numbers that reflect her or his uncertainty. This supports more reasonable commitments and less adversarial conversations. In the tool, the numbers are rolled up using a Monte Carlo algorithm that accounts for task dependencies and shows the likelihood of completing the iteration or scrum. A benefit of this approach is that the worker can be held accountable not to a single value, but to staying within the range of estimate and so need there is no need for padding. There remains the problem of knowing if the estimate is reasonable and how to find the meritorious, which finally brings us to the client request.
The client asked if we could turn this around. Could we use some sort of algorithm to compute the expected time to complete for the task? In other words, the system tells the worker the amount of time it should take to complete the task and the worker then is measured against this expectation. As I said at the beginning of the blog, my first reaction is 'probably not' and this is undesirable. Lets dive deeper. First, like the RTC agile planner, this computation can and should include some best, likely, and worse case in order not to be overly oppressive and roll up to show iteration and/or project schedule risk. Further, building out this approach raises the following statistical question: "Can we sort work items into equivance classes of similar enough tasks, so that we use these classes as populations to build time-to-complete statistics?" If we could do this, then we could properly set expectations on the worker, detect the superior and inferior workers, reward the former and better train the latter. Further, we could measure improvements over time in the execution of the tasks due to team or proecess improvements. All good things. However, this approach needs to be implemented very carefully and not over applied or it could lead to more oppresion and untended consquence.
I suspect the more creative architecture and design tasks simply do lend themselves to this sort of analysis. So teams that create new platforms and build new applications will rely more on expert opinion for the estimates and not predictions solely based on historical data. Not everyone would agree with this. For example, there are some estimation tools provided by various vendors that in fact do try to estimate design and architecture tasks effort and duration by using parametric models or classifications. However, there is so much variation in the amount of novelty of the efforts and the team skill and experience, the uncertainties in the estimates are large enough that they that they should be applied to projects with great care and to individuals not at all.
On the other hand, most of what development organizations do is more routine and for those tasks something along the lines of what the customer asked for might be possible. One would need a way of characterizing the different task classes, track the times-to-complete and do the statistical measures. With this in place, one could explore not only automated task estimates, but also process optimzation by what I believe is a novel application of statistical process control.
In summary I believe we need to pursue task analytics and estimation, but I have serious misgivings. Automated analytics-based business processes can go seriously wrong. We need to ensure that some judgment and subjectivity is part of the process. The misuse of analytics in the subprime mortgage business is a case in point
I realize something along the lines I am describing may already be available. Has anyone heard of a tool that supports this method?
Yesterday, I was at the Conference on System Engineering Research (CSER) held this year at Stevens Institute. I sat through a talk which stimulated my curmudgeon tendencies. In the spirit of hopefully generating some contraversy, I will not hold back.
The talk was about an expert-system based engineering risk management system. Essentially, the authors got a set of experts together to identify catagories of risks (people, delivery, product ...), risks in the categories, and a method for identifying level of risk and their consequence and then summing the products of the levels and the consequences. The end is the total amount of category risk. Looking at the output is supposed to give you insight of the overall program risk and the contributing risks.
My problem is that I cannot parse the last sentence. In fact I do not understand terms like "program risk" and say "people risk". There may be a clash of cultures here; to many those terms seem reasonable.
My argument starts here: One can ask 'What is my risk of going over budget?' or 'what is my risk of missing the delivery date?' The answers to these sort of questions are answered using stardard business analytics. See, for example, Mun's text on risk analytsis that defines risk as statistical uncertainty of a quantity that matters. For example, 'time to complete' is a quantity that does matter to a project. The uncertainty in making the date can be measuresd as the variance (or standard deviation) of the estimate of the time-to-complete. (Note, for the math aware, time-to-complete is what the statisticians call a continuous random variable.) So the answer to the question, 'what is my schedule risk?' has an unambiguous, quantified answer. What is 'my people risk' has no such answer. In fact, 'people risk' is not a concept defined in business analytics.
Of course, it does make sense to ask what contributes to the schedule risk. One might fear that the inability to staff the project contributes to the schedule risk. Fair enough. In my mind, that does not make staffing a 'risk', but say a schedule risk factor.
I am not sure why I am so adamant about this, but I am. It could be that I believe that the less precise use and measurement of risk is holding our industry back.
Anyone want to comment or defend the so-called risk management practice underlying the talk I found so annoying ?
I have mentioned in the first posting, I am still getting the hang of blogging. I guess one use of blogs is to share what on my mind while staying in the neighborhood of the topic of analytics. So, I have been putting a lot of thought to Toyota's diemma about how to deal with the reports of dangerous acceleration in their cars. The recent reports of Prius incidents (see this article in the New York Times) confirmed some of my earlier suspicions and hence this blog.
First, I need to come clean; all I know is from news accounts. I have had no contact with Toyota or any IBMers working with Toyota. Further, I need to say the the opinions here, in my opinion not controversial, are my own and do not reflect any IBM position.
So what do we know:
Now, say there is one chance in a million miles of driving of the latent defects manifesting. They may be impossible to find with standard testing and will inevitably happen every so often to drivers. This is the standard insight that with large volumes unlikely events become inevitable. So with Toyota's large sales, they may be the victim of their success.
The avionics community has developed a discipline around safety-critical software. There are design and model testing methods to validate that the embedded software is good enough to stake people's lives on the code running correctly. (There is a good article is the latest Communications of the ACM on model checking for avionis) It seems Toyota and the entire auto industry needs to adopt these safety-critical disciplines going forward. The cost of these practices is overshadowed by the costs of costs of the highly publicized incidents, the suits, and other liability.
Some business analytics for development organization entrail measureing return on investment for software and system programs. I just finished a long version of our RoI approach. This is a link to a more technical version of the paper..
I would like to build on the theme of reasoning about what to measure. The goal of business analytics is to track what matters to the organization (what it is you are trying to manage) and respond to the measure in some way to gain improvement. The science of measuring outcomes and In manufacturing and some service delivery domains is statistical process control (SPC), SPC lies at the heart of the Six Sigma movement. Even so, there will be no need to have a 6-six sigma belt to participate in this discussion . While there is reason to believe that not all of the Six Sigma practices do not apply all that well to our domain, the idea of tracking outcomes, applying statistical analysis to detect change change, and applying some sort of controls to affect the change applies in all business domains, including software and system development and delivery.
Briefly then, the outcomes are the operational goals and controls are the actions you take to achieve the outcomes, So naturally we need too kinds of measures.
The simplest way, for me at least, to think about SPC is to measures trends in outcome measures and control measures to determine the likelihood that the controls are in fact affecting the outcome. In our potato chip example we might find that we cannot control the outcome well enough by the shaker and belt controls. In that case, we might look for some other factor to control, say the factory humidity.
If you look at many measurement programs in software and system you often find that outcome and measures are confused. In fact even sorting the measures into the two buckets is hard. No wonder measured process improvement for our domain has been so hard.Anyone have good examples of measurement patterns or antipatterns of measuring controls and outcomes?
Again stay tuned for more....
In a conversation with a development lab productivity team, I was reminded that the first challenges software and system organizations face when starting an improvement program is 'what to measure'. In particular, some organizations start with what is easy to measure with the understandable thought "we need to start somewhere". I have found this approach tends not get traction. Over the years I have settled on some principles that seem to apply:
I suspect there some other principles that should be added. But these are a good start.
In a later blog, I will discuss levels of measurement.