141–150 of 193 posts
I think it depends I work on a large enterprise product we are generally within 20% of the estimate. If some prominent team members were not aggressive in planing that figure would be smaller. Average age on the team is over 40 avg experience around 20 years.
I can’t accurately estimate non-trivial software. I’ve never met anybody who can accurately estimate non-trivial software. I’ve never seen anybody claim to be able to accurately estimate non-trivial software. Yet for some reason people still insist that estimating non-trivial software is not only possible, but trivial.
>Yet for some reason people still insist that estimating non-trivial software is not only possible, but trivial. It's always maddening to get into debates about this stuff with project managers who believe this nonsense. I know the Fibonacci point scale is supposed to address this by giving PMs something , but I've only ever seen it turn into time-estimates-by-proxy. These days, I only ever give estimates in terms of…
I ask first will the task take 20 years to finish and they usually laugh and say of course not. Then I ask what about 20 seconds and they laugh again. We keep going on both sides of the boundary until they stop laughing and it starts sounding more reasonable.
Then I have something to work with like 3 to 6 months which gives me more options. I can accept the risk or I can take other steps to reduce it or break it into more manageable bites. It’s not perfect but it’s worked pretty well.
If I was asked to give some hints, I would say:
- in optimistic and pessimistic cases don't fear to use extreme values
- don't estimate on your own, take reasonable amount of developers with variety of experiences
- don't give exact value to client, give probabilities ("it is very likely that we will be deliver this in between X and Y man-hours/days)
All estimates I made using PERT were quite accurate (<5% time difference between estimated and real execution)
How did you manage to constrain the time overrun to only 4x? As a mercenary engineer, I've had to answer the estimation question many times. Whenever I've given estimates, it has only ever shot me in the foot. Spolsky might have figured it out, but I haven't. So I try to avoid giving estimates as far as possible and instead focus on demonstrating velocity of a working system they can choose to stop funding at any tim…
An easy example is the thousands of JSON APIs you can integrate these days, where the code to do that is almost identical, but not quite. Generally the only complications are in what stupid authentication and pagination method this API came up with.
But it happens everywhere in coding. Every system might need user management, but slightttttly different each time. Or sending emails but Bob already uses Sendgrid, where traditionally you've used mailgun.
Also the software industry changes all the time. That email code you wrote ten years ago using SMTP won't be reusable. The invoicing system you built for one client using PHP and jQuery 1.7 in 2012? Not appropriate to sell to a client today.
Basically you should have written things at least very similar to what you're estimating on. Then you need to find your "multiplier". The figure you need to increase your gut estimate by to get the real estimate.
Plus, there's a lot of legal complication about reusing code with different clients, often you should be rewriting purely to be safe for them and you from a copyright perspective.
I can’t accurately estimate non-trivial software. I’ve never met anybody who can accurately estimate non-trivial software. I’ve never seen anybody claim to be able to accurately estimate non-trivial software. Yet for some reason people still insist that estimating non-trivial software is not only possible, but trivial.
OP here - it's just (somehow, repeatedly) surprising the magnitude to which you can be wrong, even when it's just you and there's no pressure from anyone else to get it done quickly and it's really just an honest guess. I see this over and over again with people I know bootstrapping projects - the over optimism I think is just part of being a builder. Sometimes in startup circles there seems to be this meme of how yo…
How did you manage to constrain the time overrun to only 4x? As a mercenary engineer, I've had to answer the estimation question many times. Whenever I've given estimates, it has only ever shot me in the foot. Spolsky might have figured it out, but I haven't. So I try to avoid giving estimates as far as possible and instead focus on demonstrating velocity of a working system they can choose to stop funding at any tim…
Having done hundreds of small to mid sized projects I take comfort in the fact estimating is a very distinct task that even the best of developers learn last. I've got three tricks in my pocket that at least help me with this: The first is that I go by the formula mentioned in "The Mythical Man-Month" — which is that the effort in larger projects is distributed as follows: 1/3 planning 1/6 coding 1/4 component test a…
Developer experience. I've been working as a developer for a living for 18 years & I thought I was pretty hot-shit 10 years ago already, but I can probably do more today in 4 days than I used to in 4 weeks (or 4 months a few years before that).
The idea is to learn as much as possible (read The Lean Startup if you haven't). If you build too much in one go, you're going to have tied yourself to one vision of how your users will use the product and be more closed to learning from them what they actually need. Note that you were persuaded by a designer to make the design nicer, not a user, potential user or even product manager.
What was the problem with launching, and then deciding that design was the next priority and working on it while your product was running?
[disclaimer: I definitely haven't got this figured out as we shutdown the company and I'm back building Big Expensive Systems]
How did you manage to constrain the time overrun to only 4x? As a mercenary engineer, I've had to answer the estimation question many times. Whenever I've given estimates, it has only ever shot me in the foot. Spolsky might have figured it out, but I haven't. So I try to avoid giving estimates as far as possible and instead focus on demonstrating velocity of a working system they can choose to stop funding at any tim…
For me Joel was spot on in my experience, and I disagree, you are always writing the same code again and again. Just tweaking it a bit to fit the requirements. An easy example is the thousands of JSON APIs you can integrate these days, where the code to do that is almost identical, but not quite. Generally the only complications are in what stupid authentication and pagination method this API came up with. But it hap…
"Think of me more like being a journalist. You want a good story and have a rough idea, so I will find the right people and interview them (domain experts, business people), try to figure out how to distill their knowledge into something that is both accurate, yet not too detailed and most importantly has to fulfill the needs of my readers/users (easy to read, yet super insightful, with some pretty images etc.). Wheter the article is about nuclear physics or siamese koalas is secondary, the process is more or less the same, yet I am neither a koala expert nor a nuclear scientist. You are the expert."
I also try to explain why I am unsure about estimating even relatively small tasks like this:
"You know restaurant (or another famous location) Y, right? We both know how to walk, I mean we have had like 30 years of experience in doing that, correct? So how many minutes does it take you to walk from here to restaurant Y?". The more people in the group, the more interesting it might get. Estimates usually differ by a factor of 2-4. People usually cannot even correctly estimate a trivial thing like taking a walk.