Category Archives: lean

The No Estimates principle: The importance of knowing when you are wrong

You started the project. You spent hours, no: days! estimating the project. The project starts and your confidence in its success is high.

Everything goes well at the start, but at some point you find the project is late. What happened? How can you be wrong about estimates?

This story very common in software projects. So common, that I bet you have lived through it many times in your life. I know I have!

Let’s get over it. We’re always wrong about estimation. Sometimes more, sometimes less and very, very rarely we are wrong in a way that makes us happy: we overestimated something and can deliver the project ahead of (the inflated?) schedule.

We’re always wrong about estimation.

Being wrong about estimates is the status quo. Get over it. Now let’s take advantage of being wrong! You can save the project by being wrong. Here’s why…

The art of being wrong about software estimates

Knowing you are wrong about your estimates is not difficult after the fact, when you compare estimates to actuals. The difficult part is to make a prediction in a way that can tested regularly, and very early on – when you still have time to change the project.

Software project estimates as they are usually done, delay the feedback for the “on time” performance to a point in time when there’s very little we can do about it. Goldratt grasped this problem and made a radical suggestion: cut all estimates in half, and use the rest of the time as a project buffer. Pretty crazy hein? Well, it worked because it forced projects to face their failures much earlier than they would otherwise. Failing to meet a deadline early on in the life-cycle of the project gave them a very powerful tool in project management: time to react!

The #NoEstimates approach to being wrong…and learning from it

In this video I explain shortly how I make predictions about a possible release date for the project based on available data. Once I make a release date prediction, I validate it as soon as possible, and typically every week. This approach allows me to learn early enough when I’m wrong and then adjust the project as needed.

We’re always wrong, the important thing is to find out how wrong, as early as possible

After each delivery (whether it is a feature or a timebox like a sprint), I update my prediction for the release date of the project based on the lead time or throughput rate so far. After updating the release date projection, I can see whether it has changed enough to require a reaction by the project team. I can make this update to the project schedule without gathering the whole team (or “the chosen ones”) into a room for an ungodly long estimation meeting.

If the date has not changed outside the originally interval, or if the delivery rate is stable (see the video), then I don’t need to react.

When the release date projection changes to a time outside the original interval, or the throughput rate has become unstable (did you see the video?), then you need to react. At first to investigate the situation, and later to adjust the parameters in your project if needed.

Conclusion

The #NoEstimates approach I advocate will allow you to know when the project has changed enough to warrant a reaction. I make a prediction, and (at least) every week I review that prediction and take action.

Estimates, done the traditional way, also give you this information, but too late. This happens because of the big-batch thinking the reliance on estimations enables (larger work items are ok if you estimate), and because of the delayed dependency integration it enables (estimated projects typically allow for teams that are dependent to work separately because of the agreed plan).

The #NoEstimates approach I advocate has one goal: reduce feedback cycle. These short feedback cycles will allow you to recognise early enough how wrong you were about your predictions, and then you can make the necessary adjustments!

Picture credit: John Hammink, follow him on twitter

How to choose the right project? Decision making frameworks for software organizations

Frameworks to choose the best projects in organizations are a dime a dozen.

We have our NPV (net present value), we have our customized Criteria Matrix, we have Strategic alignment, we have Risk/Value scoring, and the list goes on and on.

In every organization there will a preference for one of these or similar methods to choose where to invest people’s precious time and money.

Are all these frameworks good? No, but they aren’t bad either. They all have some potential positive impact, at least when it comes to reflection. They help executive teams reflect on where they want to take their organizations, and how each potential project will help (or hinder) those objectives.

So far, so good.

“Everybody’s got a plan, until they get punched in the face” ~Tyson

Surviving wrong decisions made with perfect data

However, reality is seldom as structured and predictable as the plans make it out to be. Despite the obvious value that the frameworks above have for decision making, they can’t be perfect because they lack one crucial aspect of reality: feedback.

Models lack on critical property of reality: feedback.

As soon as we start executing a particular project, we have chosen a path and have made allocation of people’s time and money. That, in turn, sets in motion a series of other decisions: we may hire some people, we may subcontract part of the project, etc.

All of these subsequent decisions will have even further impacts as the projects go on, and they may lead to even more decisions being made. Each of these decisions will also have an impact on the outcome of the chosen projects, as well as on other sub-decisions for each project. Perhaps the simplest example being the conflicts that arise from certain tasks for different projects having to be executed by the same people (shared skills or knowledge).

And at this point we have to ask: even assuming that we had perfect data when we chose the project based on one of the frameworks above, how do we make sure that we are still working on the most important and valuable projects for our organization?

Independently from the decisions made in the past, how do we ensure we are working on the most important work today?

The feedback bytes back

This illustrates one of the most common problems with decision making frameworks: their static nature. They are about making decisions “now”, not “continuously”. Decision making frameworks are great at the time when you need to make a decision, but once the wheels are in motion, you will need to adapt. You will need to understand and harness the feedback of your decisions and change what is needed to make sure you are still focusing on the most valuable work for your organization.

All decision frameworks have one critical shortcoming: they are static by design.

How do we improve decision making after the fact?

First, we must understand that any work that is “in flight” (aka in progress) in IT projects has a value of zero, i.e., in IT projects no work has value until it is in use by someone, somewhere. And at that point it has both value (the benefit) and cost (how much we spend maintaining that functionality).

This dynamic means that even if you have chosen the right project to start with, you have to make sure that you can stop any project, at any time. Otherwise you will have committed to invest more time and more money (by making irreversible “big bang” decisions) into projects that may prove to be much less valuable than you expected when you started them. This phenomenon of continuing to invest beyond the project benefit/cost trade-off point is known as Sunk Cost Fallacy and is a very common problem in software organizations: because reversing a decision made using a trustworthy process is very difficult, both practically (stop project = loose all value) and due to bureaucracy (how do we prove that the decision to stop is better than the decision to start the project?)

Can we treat the Sunk Cost Fallacy syndrome?

While using the decision frameworks listed above (or others), don’t forget that the most important decision you can make is to keep your options open in a way that allows you to stop work on projects that prove less valuable than expected, and to invest more in projects that prove more valuable than expected.

In my own practice this is one of the reasons why I focus on one of the #NoEstimates rules: Always know what is the most valuable thing to work on, and work only on that.

So my suggestion is: even when you score projects and make decisions on those scores, always keep in mind that you may be wrong. So, invest in small increments into the projects you believe are valuable, but be ready to reassess and stop investing if those projects prove less valuable than other projects that will become relevant later on.

The #NoEstimates approach I use allows me to do this at three levels:

  • a) Portfolio level: by reviewing constant progress in each project and assess value delivered. As well as constantly preparing to stop each project by releasing regularly to a production-like environment. Portfolio flexibility.
  • b) Project level: by separating each piece of value (User Story or Feature) into an independent work package that can be delivered independently from all other project work. Scope flexibility.
  • c) User Story / Feature level: by keeping User Stories and Features as small as possible (1 day for User Stories, 1-2 weeks for Features), and releasing them independently at fixed time intervals. Work item flexibility

Do you want to know more about adaptive decision frameworks? Woody Zuill and myself will be hosting a workshop in Helsinki to present our #NoEstimates ideas and to discuss decision making frameworks for software projects that build on our #NoEstimates work.

You can sign up here. But before you do, email me and get a special discount code.

If you manage software organizations and projects, there will be other interesting workshops for you in the same days. For example, the #MobProgramming workshop where Woody Zuill shows you how he has been able to help his teams significantly improve their well-being and performance. #MobProgramming may well be a breakthrough in Agile management.

Picture credit: John Hammink, follow him on twitter

What is Capacity in software development? – The #NoEstimates journey

I hear this a lot in the #NoEstimates discussion: you must estimate to know what you can deliver for a certain price, time or effort.

Actually, you don’t. There’s a different way to look at your organization and your project. Organizations and projects have an inherent capacity, that capacity is a result of many different variables – not all can be predicted. Although you can add more people to a team, you don’t actually know what the impact of that addition will be until you have some data. Estimating the impact is not going to help you, if we are to believe the track record of the software industry.

So, for me the recipe to avoid estimates is very simple: Just do it, measure it and react. Inspect and adapt – not a very new idea, but still not applied enough.

Let’s make it practical. How many of these stories or features is my team or project going to deliver in the next month? Before you can answer that question, you must find out how many stories or features your team or project has delivered in the past.

Look at this example.

How many stories is this team going to deliver in the next 10 sprints? The answer to this question is the concept of capacity (aka Process Capability). Every team, project or organization has an inherent capacity. Your job is to learn what that capacity is and limit the work to capacity! (Credit to Mary Poppendieck (PDF, slide 15) for this quote).

Why is limiting work to capacity important? That’s a topic for another post, but suffice it to say that adding more work than the available capacity, causes many stressful moments and sleepless nights; while having less work than capacity might get you and a few more people fired.

My advice is this: learn what the capacity of your project or team is. Only then you will be able to deliver reliably, and with quality the software you are expected to deliver.

How to determine capacity?

Determining the capacity of capability of a team, organization or project is relatively simple. Here’s how

  • 1- Collect the data you have already:
    • If using timeboxes, collect the stories or features delivered(*) in each timebox
    • If using Kanban/flow, collect the stories or features delivered(*) in each week or period of 2 weeks depending on the length of the release/project
  • 2- Plot a graph with the number of stories delivered for the past N iterations, to determine if your System of Development (slideshare) is stable
  • 3- Determine the process capability by calculating the upper (average + 1*sigma) and the lower limits(average – 1*sigma) of variability

At this point you know what your team, organization or process is likely to deliver in the future. However, the capacity can change over time. This means you should regularly review the data you have and determine (see slideshare above) if you should update the capacity limits as in step 3 above.

(*): by “delivered” I mean something similar to what Scrum calls “Done”. Something that is ready to go into production, even if the actual production release is done later. In my language delivered means: it has been tested and accepted in a production-like environment.

Note for the statisticians in the audience: Yes, I know that I am assuming a normal distribution of delivered items per unit of time. And yes, I know that the Weibull distribution is a more likely candidate. That’s ok, this is an approximation that has value, i.e. gives us enough information to make decisions.

You can receive exclusive content (not available on the blog) on the topic of #NoEstimates, just subscribe to the #NoEstimates mailing list below. As a bonus you will get my #NoEstimates whitepaper, where I review the background and reasons for using #NoEstimates

Picture credit: John Hammink, follow him on twitter