A modular approach to CMOS process development requires an understanding of individual process modules (channel, gate, etc.) and their interactions. The reverse short channel effect, (RSCE) in NMOS devices is one such interaction between the channel and source/drain (S/D) modules. Similarly the interaction between the S/D and silicide modules affects the contact and gate sheet resistance. This paper presents (a) an investigation of the effects of S/D processing (As and P implant conditions) on the RSCE, (b) effects of S/D and silicide processing on the contact and gate sheet resistance, (c) the use of an integrated system to optimize process modules and their interactions and (d) the validity of the modules and system in process development by obtaining a 4% improvement in drive current of a 0.25 micron NMOS device. The outputs of the S/D module include the doping profiles as a function of implant and anneal conditions. The interaction between the channel and S/D is caused by the damage created during the S/D implants, leading to channel dopant redistribution during subsequent thermal anneals. This interaction causes the RSCE in NMOS devices and has to be taken into account before the modules can be used for process optimization. The interaction is studied by varying the dose and energy of the As and P S/D implants and observing their effect of the RSCE. Further, to model this interaction, parameters of a 2D dopant profile model are extracted from device data and form a part of the S/D module in addition to the doping profile information. The system integrates the outputs from the process modules and their interactions and allows for a rapid search of the process space. The search criteria can be varied to include performance (e.g. drive and off current) and manufacturability criteria.