enterprise information systems
(EIS) is usually associated with high costs. It is therefore crucial to understand those factors that determine or influence these costs. Existing cost analysis methods are difficult to apply. Particularly, these methods are unable to cope with the dynamic interactions of the many technological, organizational and project-driven cost factors, which specifically arise in the context of EIS. Picking up this problem, in previous work we introduced the EcoPOST framework to investigate the complex cost structures of EIS engineering projects through qualitative cost evaluation models. This paper extends this framework and introduces a pattern-based approach enabling the reuse of EcoPOST evaluation models. Our patterns do not only simplify the design of EcoPOST evaluation models, but also improve the quality and comparability of cost evaluations. Therewith, we further strengthen our EcoPOST framework as an important tool supporting EIS engineers in gaining a better understanding of those factors that determine the costs of EIS engineering projects.