An EVM System is the set of procedures and practices that are used to provide an EVM capabilty in project management. It commonly includes an automated product to support the calculations, but it is not necessary.

I think, what makes a system too rigid is the lack of choices. If your documentation only allows 2 EV measurement techniques, that is too rigid. If you system descripiton says you must use a defined WBS to x levels, that is too rigid.

On the other hand if it says you have to have a WBS with a description of the work at each level and it is changed only by an approved change order, that is not rigid, that is effective management and change control.

I recently heard the VP of Project Performance at SAIC (MS. Kathleen Hedges) describe the standard EVM system that is used for all projects. But those requirements are at a high level so each project has some latitude to set up project specific desk instructions that may vary from the company standard. By having a company standard, they get greater efficencies, the ability to view all projects together with common metrics and everyone understands what it means without being retrained.

I will summarize that EVM is not too rigid. The way it is implemented may cause it or any other practice to be too rigid.

Mark

About the only thing I would add is a warning that making changes to the scope results in some pretty bizarre looking S curves, and requires frequent rebaselining if the S curve is to mean anything.

For those looking for more information, Dr. Joseph Orczyk wrote a chapter in AACE’s “Skills and Knowledge of Cost Engineering, 5th Edition” https://www.aacei.org/PortalTools/Shopper/ProductDetail.cfm?ProdCompanyPassed=1&ProdCdPassed=1-1545-02 that details several approaches to implementing Earned Value under conditions where the budgets are variable or changing.

Thanks again for the good articles… Keep them coming.

BR,
Dr. PDG, Jakarta