A method for sizing a computer system. Toolsets defining required performance of a subsystem, as well as hardware and software resources available to the subsystem, are transmitted to a subsystem provider. The subsystem provider responds with information about a subsystem that specifically comports with the toolset's definitions of performance and available resources. Whether two subsystem providers respond to a same toolset for a same subsystem or to different toolsets for different subsystems, the two subsystem providers are blocked from viewing the other subsystem provider's response. Further, each subsystem provider's response includes only information needed to comport with the toolset, thus preventing unnecessary disclosure of specifications of the subsystem beyond those defined in the toolset.