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Why software projects take longer than you think: a statistical model (2019)

erikbern.com

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Re: Why software projects take longer than you think: a statistical model (2019)

#3
I tend to be skeptical of statistical analyses like this.

At the end of the day, it's usually someone who is paying or funding a task, and someone who will perform the task. The person performing the task wants to please the person funding it (in order to secure that funding). This commonly involves minimizing difficulty and giving optimistic estimates.

People who give straight answers (something like: this is really hard, it will take a lot of time, there are lots of unknowns, and might not be achievable given the budget) won't get the award. Those who overdo the bullshit and give transparently falsely optimistic estimates will not receive it either. So those who fall in the middle do end up getting the award.

TLDR being, model this effect Game Theoretically, where the "blowup factor" is derived from a Nash equilibrium between counterparties playing optimal strategies seeking to optimize their payoff.

Finally, take three companies: Company A delivers a project in 50% of the time, and 50% under budget. Company B fails to deliver the project, after consuming 100% of the budget. Company C completes 90% of the project with 100% of the funding, and only needs 20% more money to finish it. The customer will most likely top them off, because they are so close, and it's a sunk cost.

Who makes the most money? Company C. Who is the biggest loser? Company A (despite being the best). Anyway, for my next trick, I'll explain why this same effect causes agile to make everything take longer, cost more, and make everyone more miserable.

Re: Why software projects take longer than you think: a statistical model (2019)

#4
post #3

I tend to be skeptical of statistical analyses like this. At the end of the day, it's usually someone who is paying or funding a task, and someone who will perform the task. The person performing the task wants to please the person funding it (in order to secure that funding). This commonly involves minimizing difficulty and giving optimistic estimates. People who give straight answers (something like: this is really…

I'd love to hear your standpoint on the agile.

Re: Why software projects take longer than you think: a statistical model (2019)

#5
post #4
post #3

I tend to be skeptical of statistical analyses like this. At the end of the day, it's usually someone who is paying or funding a task, and someone who will perform the task. The person performing the task wants to please the person funding it (in order to secure that funding). This commonly involves minimizing difficulty and giving optimistic estimates. People who give straight answers (something like: this is really…

I'd love to hear your standpoint on the agile.

Agile plays this scenario out every two weeks, instead of once per project.

Re: Why software projects take longer than you think: a statistical model (2019)

#6
post #3

I tend to be skeptical of statistical analyses like this. At the end of the day, it's usually someone who is paying or funding a task, and someone who will perform the task. The person performing the task wants to please the person funding it (in order to secure that funding). This commonly involves minimizing difficulty and giving optimistic estimates. People who give straight answers (something like: this is really…

How does the ABC example extends to repeated games?

Re: Why software projects take longer than you think: a statistical model (2019)

#7
Manfred Schroeder's "Fractals, chaos, power laws" (1991) had a similar statistical distribution (Levy? or something else?) which reminded me very much of software. Basically, the longer something has been observed to remain uncompleted, the further away the expected date of completion becomes. If you have to slip, slip big.

Re: Why software projects take longer than you think: a statistical model (2019)

#8
The hardest part of this is communicating it to a client. “What do you mean it will probably take 5 weeks, but could take between 2 and 10 weeks? That’s a pretty big span. The other programmer I asked promised it would be done in 5, period. Are you sure you know what you’re doing?”

Re: Why software projects take longer than you think: a statistical model (2019)

#9
Over the course of my life I've designed and built many products/projects. Not a single one that had deadlines imposed by the customer was late. It might deviate on non critical feature set but the main course has been always served properly.

Re: Why software projects take longer than you think: a statistical model (2019)

#10
post #3

I tend to be skeptical of statistical analyses like this. At the end of the day, it's usually someone who is paying or funding a task, and someone who will perform the task. The person performing the task wants to please the person funding it (in order to secure that funding). This commonly involves minimizing difficulty and giving optimistic estimates. People who give straight answers (something like: this is really…

Would love to hear your take on agile. You should write a "blog" post about it... Company A would eventually get a good reputation and win in the long run.
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