The purpose of a Process Development Execution System (PDES) is to manage and support the execution of development activities for high-tech manufacturing processes. A simplistic relational perspective is that a PDES is to the development of high-tech manufacturing processes what a Manufacturing Execution System (MES) is to the execution of volume production processes. The significant difference between the two systems is that the emphasis of the PDES toolset is to deliver enormous flexibility and experimentation freedom in a low volume environment, while the tools of a MES focus on less variance, tighter controls, and logistics in a high volume environment.

The similarities in purpose of a PDES and MES are the traditional common-ground objectives of increasing traceability, productivity, and quality. With a PDES, the expectation and objective is to increase the quality of the developed manufacturing process, which is somewhat in contrast to the objective of improving production quality with a MES.

A more comprehensive description of the PDES software tool category can be found in Wikipedia.