How to Solve the Fixed Scope, Fixed Date Commitment Paradox
07 min read 1998
Hey there, my name is Sonya Siderova, I’m the founder and CEO of Nave and I help managers hit their targets consistently without overburdening their teams. This week’s post is about commitments and how to avoid the bias towards that duty-obligation-promise way of thinking.
“We’ll deliver these 10 items by next Thursday!”.
What’s the problem with this statement?
There are two major issues with it.
Firstly, it suggests that there is an actual obligation to deliver all of the 10 items by next Thursday. And secondly, it implies that these exact 10 items will be finished by then.
Can we make that promise knowing that knowledge work is notorious for its unpredictable nature?
We should always remember that there is uncertainty involved and we should communicate that there are more than one possible scenario that might happen in the future.
The Flaw of Fixed Scope, Fixed Date Commitment
Let’s break down this statement.
Delivering “all of the 10 items by next Thursday” means that you are fixing both the scope and the end date. And you should never do that.
Then, finishing “these exact 10 items” means that you assume there won’t be any additional work coming in between, the priority of your tasks will stay the same and there won’t be any issues or emergencies popping up along the way. Can you really commit to that?
The future is not deterministic. There is no model that provides a 100% certainty that something will happen in the future. There are always multiple outcomes that may occur. By Thursday, you may deliver 10 items, or a little bit less or perhaps a little bit more.
The only thing you can do to get closer to what will actually happen is to manage the uncertain and unknown effectively. So, how can we get there?
Why Forecasting Is a Better Idea
Instead of committing to a fixed date and scope, provide a forecast.
A forecast looks like this: “We can deliver 10 items by next Thursday with an 85% probability of hitting that target.”
What does this statement say?
First, you can take any 10 items from your backlog, and yes, feel free to add and remove from that list. As long as the work hasn’t been started yet, you can switch the priorities as many times as you want. The forecast will still be valid.
Second, you communicate the risk you are managing in terms of percentages. There is an 85% chance you will make it on time.
Not willing to live with that much risk? Then, go with a 95% certainty and reduce the number of items. I’ll show you how to do that in just a moment, so bear with me here.
When you make delivery predictions, use the term forecast. It may seem to be a simple wording change, but it will have significant implications.
Let’s take a step back and remind ourselves why we need to make delivery predictions in the first place.
Remember, the primary purpose is to mitigate the risk of failure as much as possible. So, what is the approach to reducing the risk of failure?
Let’s explore how to make a delivery forecast using the Throughput Histogram.
The Throughput Histogram shows the number of items you completed in a certain period. Let’s assume you release new updates every 2 weeks. To track the number of tasks delivered, we will group our data by 2 weeks and we will set the start date of the chart to match the last release date.
Looking into the example above, we can see that there was 1 release in which this team managed to deliver 5 items, 2 releases in which they finished 10 items, 1 release with 12 items, another 2 releases with 14 items, and so on. This analysis reveals your team’s capacity.
Let’s Dig Into the Numbers
This team can deliver at least 5 items per release. This is their absolute minimum. They guarantee that they will deliver at least 5 items and that goal comes with a 95% certainty that this will happen.
Then, there is an 85% chance that they will deliver at least 10 items and a 70% chance that they will finish more than 12 items. The chance that they will complete 14 items drops down to about 50%.
Even though this team managed to finish 24 items in one of their previous releases, it is unlikely that they will be able to complete that much work consistently. The probability that comes with this goal is less than 30%. If they go with that number, it is very likely that some of the work will be rescheduled for the next iteration.
If the work is complex, there are lots of unknowns and you expect obstacles along the way, then go with the 95th percentile to reduce the risk of failure. Schedule 5 items instead. You will probably deliver more, but not less than 5 items and that promise comes with very high confidence that you’ll keep it.
That’s how you manage the uncertain and unknown in an effective way.
The question of “When will this be done?” is not that interesting anymore. The charts already provide that answer for you. The question now is, how much risk are you willing to take?
We’re mitigating the risk of failure by choosing higher percentiles to work with.
The Only Prerequisite to Making Any Approach to Forecasting Work
Now, you may wonder, does this approach work if you don’t have items of the same size? It certainly does, and here is our 5-step guide to managing items of different sizes that proves it.
The size and nature of your work items don’t affect the reliability of the forecasts. The only prerequisite to making this (and any other approach) work is to optimize your delivery workflow for predictability.
If the work you’re about to handle is easy, you’ve done this before, you don’t expect any challenges along the way and most importantly, you maintain a stable delivery system, then, by all means, go with a lower percentile. Just keep in mind, the lower the probability of achieving your goals, the higher the chance of failure.
And if you are not delighted by the numbers you see on your throughput histogram, I’d like to invite you to join me inside our Sustainable Predictability program where I’ll show you the step-by-step process of building predictable workflows.
Now, we’ve prepared a guide that will equip you with practical, proven methods of making reliable future predictions based on your own past performance data. This free resource reveals several approaches, explaining in detail how they should and should not be used to make accurate delivery forecasts.
And here is your action item: Grab the complete guide to forecasting here →
Go through the guide and apply each concept in your own context using your historical performance. You’ll gain a deep understanding of what tools to use and how to use them to hit your targets consistently.
If you haven’t registered for Nave yet, you can do it here →
It’s free for 14 days, no CC required! It will take just a couple of minutes to come up with a reliable delivery forecast.
Remember that your team’s commitment is still there. It’s just not hooked up with a fixed date and scope.
The team still commits to effective collaboration, technical excellence and continuous improvement. They commit to do their best to deliver quality results in the most effective matter.
If you have friends or colleagues who are struggling to hit their targets consistently, please share this article with them. I believe this message is important to share and I’d be grateful if you spread the word.
Alright my friend, I hope you found this piece of content valuable! I’ll see you next week for more managerial goodness. Bye for now.
Meet the Author
Sonya Siderova is a passionate product manager and a driving force behind Nave, a Kanban analytics suite that helps teams improve their delivery speed through data-driven decision making. When she's not catering to her two little ones, you might find Sonya absorbed in a good heavyweight boxing match or behind a screen crafting a new blog post.
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