How much of this do I need?
The final point here is that you might not get very far through the above phases when doing a simulation study. One of the most important things to realize about simulation in practice is that much of the benefit of simulation comes from the simulation building phase of the study. The act of building a simulation causes you to have to ask your client many questions so that you can gain sufficient understanding of the process to build a simulation. This questioning process has the benefit of structuring in both your and the client's mind many thoughts about the process that had not previously been pulled together. The simulation then acts as an understandable piece of documentation about the process. It is a 'document' that is extremely easy for most people to understand (being a moving picture of the process).
We realized this quite early on in the days of Visual Interactive Simulation when we noticed that clients were very keen for us to build simulations for them but often before we were ready to formalize the experimentation process they wanted the simulation changed. The act of building the simulation itself was sufficient in some cases to enable the clients to see a new way of operating the plant that they wanted to see tested in the simulation.
The consequence of this that you will spend most of your time in the early steps of the above process and only dip into the more technical steps occasionally. It also means that the simulation building stage needs to be relatively easy and quick if you are going to be able to help your client and if your client is to be involved in this process.