Through my career, I worked for many EPCM projects. My expertise is supporting procurement systems. I supported Bechtel procurement system which is a in-house design ERP system, commercial systems such as COINs and Smartplant material, and now my preferred approach is no system. Why no system? First of all systems are expensive. There is always cost associated with database and UI license fees. Other than purchasing the system, company needs to hire consultant to perform customization.