The Goldratt technique was helpful in mapping out the conflict between CCPM/EVM that I mentioned in my last post. It’s not perfect, so please forgive it. I will make a cleaner version later, but I suspect I will be refining it later.
I have never seen an evaporating clouds with more than one prerequisite for each prerequisite. However, I found it necessary to have a requirement that stems from both EVM and CCPM. EVM and Critical Chain are not compatible because of the different behaviors they drive. EVM supports efficient behavior that focuses on tasks on the Critical Chain, which improves the project’s outcome. Critical Chain supports such behaviors. EVM supports behavior that makes it appear overall cost efficiencies have been achieved, even though those efficiencies are not critical to the project’s completion. If their EVM falls short, project managers might choose to work on less critical tasks to get a win. However, if this happens, EVM’s predictive power regarding the schedule is thrown out of the window.
This will allow you to change the budgeting and cost control tools within the Critical Chain body. It will need to use buffer management methods to cost control the project. This will allow it to be compatible with existing EVM metrics. A single project cost buffer would be created, which is already part the CCBOK. Cost buffer management would be used to control project costs. It also provides accurate EVM translations based on cost buffer utilization in relation to planned utilization.
It is important to note that all tasks must be on the Cost Critical Chain (CCC). If a task has underruns, cost overruns will result in the project going over budget. It doesn’t matter if they are in the schedule’s critical chains. This is why there is only one cost buffer, the project-cost buffer.