Research into the design processes at industrial operating companies and engineering contractors revealed that no explicit, well-defined set of quality criteria is available to judge. the final design. A well-defined set of quality factors might reduce the number of iteration loops in the design process and might also support the designer in achieving a better final design. A number of industrial case studies. and a meeting with an expert-panel provided useful insights into a possible set of quality criteria, and revealed explicit as well as implicit, : ill-defined quality criteria. The criteria as stated in the ＇Basis of Design＇ were seen as the most important quality criteria in industrial practice, however many other implicit and ill-defined criteria were also found to play an important role.The expert-panel, which consists of professionals from industry and from academia, discussed the subject thoroughly using an electronic meeting room. Many quality criteria were formulated and many ill-defined and qualitative aspects were mentioned. The expert-panel established-a ranking of the quality criteria and ill-defined criteria ranked high in the established hierarchy. An indication was given of when the most important quality criteria were introduced into the design process. This resulted in identifying a need to consider quality criteria earlier in the design process. According to the expert panel, this is still very hard to achieve in practice, therefore a system, which will be implemented as a software tool, is being developed. The tool-is designed to support the designer in defining the set of relevant explicit and implicit quality criteria, and in considering these quality criteria from the beginning to the end of the design process.