I am the Infrastructure PM on a large project, working as part of a team of PMs with different responsibilities. These include Development, Testing, Environment Support, and Implementation. My remit is limited to delivering the hardware and middleware components required to support the application.
The main technology that I have to implement in the current phase of the project is IBM WebSphere. There is no new hardware: as far as infrastructure is concerned, we are simply adding new WebSphere components to the technology stack. I have access to two specialists in the WebSphere team, as well as other ancillary specialists for the other (less prominent) technical changes that I have to make. The problem is this: each of the other PMs also needs the WebSphere guys to support their parts of the project.
We work together to align our plans, and everything looks great on paper, but the fact is that we end up scheduling 100% rather than 70% or 80% of their time, so no slack exists. And then reality kicks in. Something goes wrong: one of the tests takes longer than expected, or one of the test environments falls over, or we need to deploy new code more frequently than expected, to resolve defects in test. Any of these can mean that our plans for these scarce resources immediately fall over.
My question is this: What can I do to encourage my fellow PMs to build in a lot more slack into the project, and stop filling every minute of every day with planned work? No matter how much I try to do so, someone comes along with a new task, sees a couple of hours of apparently unoccupied time, and lays claim to it - with predictable (and disastrous) results.