Process models in management studies are quite applicable and prevalent. They often tend to be developed on the basis of qualitative and subjective approaches. The purpose of this article is to show how to develop a prescriptive process model using a quantitative method. The process model discussed in this article is on robust strategy; one which is viable regardless of what scenario happens in the environment and can thrive in a variegated environment.Although there are different techniques for robust strategy, none of them are complete and comprehensive, so the main problem can be formulated as developing a stepwise comprehensive and applied process model for designing a robust strategy, which can in its turn be used for developing strategies that are viable and reasonable in different situation.To design the process model, first, various applicable techniques were identified: Robust Decision Making (RDM), Stakeholders Analysis (SA) and Stakeholders Based Strategic Planning, Assumption Based Planning (ABP), Failure Mode and Effect Analysis (FMEA), Fault Tree Analysis (FTA), Potential Problem Analysis (PPA), Solution Effect Analysis (SEA), Uncertainty Sensitive Planning (USP), Scenario Based Planning (SBP). Second, these techniques were combined by interpretive structural modeling. The result of research (initial process model) was fed into action research as an input. The model was applied in an organization. Action, observation and reflection phases were done. Then a consensus group was used to test the utility of resultant process model.This article tried to design and propose a mix method to design a process model that makes modeling process, repeatable, clear, transparent, testable and structured. The result of research is prescriptive process model of robust strategy that is supported by observation and individual and collective reflection phases of action research.