[jiggawatts]

“It’s too hard to change the plan now.”

That one sentence alone is enough to explain the failures and I’m not even accounting for the very real cost overheads of planning.

Don’t try to change this! You can’t convince a PM that their job is not needed, their pay depends on it being a necessary function and they will fight dirty to protect that income no matter what.

[AnimalMuppet]

The very real cost and time overheads of planning.

It's not just that the plans are too rigid. It's not just that you don't know enough to plan in that much detail. It's that the planning takes time that you could be doing something useful with.

Note well: I am not advocating for no planning. I am against over planning.

[spikey_sanju]

"It's too hard to change the plan now"

+1 Agreed. Plans fail when sticking to them matters more than adapting...

TBH, the best plans know when to shift.

Flexibility > Rigidity

[jiggawatts]

This sentence isn't something I made up, it's a sentence I heard this week.

A project started a year ago, planning an infrastructure (cloud IaaS) deployment of a complex product 12 months into the future.

Now, there is a turnkey software service (SaaS) version of the product that covers the same features and more for less money and takes literally seconds to spin up.

They're stuck in the mud trying to work around complex network routing, split-DNS, and other issues with the IaaS solution. They're going to spend months applying workarounds to problems that don't need to be solved because the SaaS version has none of those problems. They're already starting to talk about getting MFA and SSO integrated Q1 next year even though the SaaS uses MFA+SSO by default.

It's incredible how much inertia these things build up, and how much time, effort, and money is wasted "sticking to the plan" even if those plans are invalidated by changes to reality.

If the project manager simply said "let's rip up the plan and use the SaaS", they'd instantly make themselves redundant and might actually be let go when their contract is up for renewal. If they keep "fighting the fight" to make a bad plan succeed, then they're the hero and will be gainfully employed for the foreseeable future.