The fact that application software are getting more and more adaptable extends the possibility of in-house developed design systems supporting design for cost. This calls for systematic methods for system development that ensure system functionality, quality and longevity.

In this work, a method supporting the development of automated systems for product design, process planning and cost estimation is introduced. The method has been the foundation on which an automated system for variant design has been developed. The system applicability as a means of gaining cost effective design is presented through studies of: multi-objective optimisation, what-if scenarios and sensitivity analyses. The work is completed by an evaluation of the three types of studies. This is followed by an evaluation of the variant design system and its underlying method (that supports in-house development of automated systems), with respect to a number of presented underlying general criteria supporting realisation of systems meeting companies’ needs.