Wednesday, October 10, 2007

Why Are You Asking Me This Question?

Any developer that's been around this industry for any length of time has found himself in a conversation like this one:

Manager: Hey, Mr. Developer, TheBusiness has decided that we need to develop a product to do XYZ. How long will that take?
Developer: Hrm... I'm not sure. What are the details of XYZ?
Mgr: The details aren't important. I just need an estimate
Dev: Well... something like 8 weeks.
Mgr: Okay, well how much longer until you finish the thing you're working on?
Dev: Around 4 weeks
Mgr: Okay. Thanks.

[10 weeks later]

Mgr: So, Dev, I'm looking forward to having this XYZ product. We've already sold it to 50 customers and they're excited to be getting it in two weeks.
Dev: WHAT?!?!?!

This is not a fun series of conversations. The breakdowns in communication should be obvious. The manager (unknowingly) expected way too much precision from the developer's estimate, and the developer gave it without nearly enough qualifying statements pointing out that it's a WAG.

So, how can this be fixed? Many developers that I know say, just don't provide the estimate. While most of us could get away with that, it doesn't necessarily help the conversation. I prefer to answer with, "Why are you asking me this question?" This is a question that I learned to ask by watching a former team lead, Glenn Burnside. Whenever a salesperson or manager would ask the team a question like, "How difficult would it be to...," Glenn's response was always the same - he would ask this question. This always resulted in a conversation that fleshed out a more detailed question (or questions) and much better, more precise answers.

The hardest part of software development is interacting with those objects that have a pulse - not those that have a system clock.


Anonymous said...

Good post.

One tip is to give your estimate in units that correspond to how certain you are about it. In your example, I would have said "about two to three months" instead of "eight weeks". If the manager presses for a more exact date, I can explain that I need more time to come up with a more precise estimate.

I'd recommend Steve McConnell's software estimation book. It has a good description of the difference between estimates and commitments and how managers and developers get confused. In your example, the manager was looking for a commitment and the developer was giving an estimate.

P.S. Good meeting you at ALT.NET.

Eric Anderson said...


Thanks for the link to the book. I had a great time meeting everyone at Alt.NET and I hope to run into you again.