A team I was coaching was coming up on an important deadline. Specific functionality had been promised for a certain date that was now eight weeks away, and they wanted to know if they were going to make it.

Using probabilistic forecasting, we determined that with 85% certainty, the remaining work could be completed in seven weeks, giving us a one week buffer.

So we pulled everyone together and talked about how we could make the date, with a small buffer, but that this was going to require us to remain completely focused. We could only work on the items that had been promised for this release and nothing else. Everyone, including the development team, the management and the business, agreed with this and they went to work.

A week later, we ran the forecast again with the latest data, and the forecast showed that with 85% certainty, they’d be done in seven weeks. Note that this is exactly the same answer we’d got a week earlier and yet they’d been busy all week. That length of time remaining should have dropped to six weeks and it hadn’t.

Was there a problem with the math? Had we done the forecast incorrectly? No and no.

They had been busy all week but the team had not worked on a single item that had been part of the “promised” set of work. There had been adhoc requests from management and the business, and bugs that had come in, and distractions from “side of desk” work that were unrelated to what they were supposed to be working on.

Despite everyone agreeing that they would focus on nothing except the promised work, they did the complete opposite. They worked on everything except that.

It would be easy to point the finger of blame. It’s harder to recognize that saying no is difficult. We all want to be helpful, and we all think “we can do this one more thing”. Everyone from management to the business to the development team had lost sight of the goal and had let other, less important, work slip in. They’d felt they couldn’t say no.

If we’re going to be effective, we need to get better at saying no.

In this particular case, they did meet the promised date but only by saying no to quite a few things. They said no to most of the incoming requests, but not to all of them. To make room for those that they kept, they said no to some of the scope that they’d previously agreed to. In other words, they delivered less in order to meet the date.