I had a discussion recently with a colleague about the usefulness of the Last Responsible Moment (LRM) in the context of a complex project. The LRM is when the Cost of Delay overweights the Benefits of Delay. In other words, it's often useful to wait with a decision until a certain point - last responsible moment - before the cost of making a decision too late will be higher than the benefits. I want to come up with an example that may happen quite often in a project:
Lets assume you want to order server hardware that will host your web application. If you order it very early, you may not have enough information to buy the hardware properly sized. Later in the project you may have enough information to make the decision about the hardware sizing. But ordered too late there is a risks that the hardware will not be up and running before the release date and you will loose some expected income from your web application.
We came to the conclusion that the LRM makes practically no sense. The only thing we know is that not all decisions have to be made in the beginning. The nature of complexity is that we cannot plan all details in advance. Only after a project has finished, we know exactly which decisions have been made correctly. Although there exists a LRM, we cannot find it in advance (in complex software projects). By focusing too much to find the LRM in advance, we may actually risk that some business value is not delivered.
Of cause, if we can quantify the Cost of Benefit and Delay then we can find the LRM. It may also help us to know about the LRM while we are still making decisions trusting our guts. But agile coaches should teach the whole story, so people avoid gambling for the LRM.