Abstract

Designing and building complex artifacts like simulation models often rely on the strategy of modularity. My main claim is that the validation of simulation models faces a challenge of holismHolism because modularityModularity tends to erode over the process of building a simulation model. Two different reasons that fuel the tendency to erosion are analyzed. Both are based on the methodologyMethodology of simulation, but on different levels. The first has to do with the way parameter adjustment works in simulation; the second comes from how different groups of software programmers work together. The chapter will conclude by drawing lessons about how holism challenges the validation of simulation and by discussing a corollary to conformational holism: the boundary between validation and verification tends to become blurred, thus undermining a strategy that insists on keeping them separate.