In the HATS project three candidate case studies are considered. The purpose of case studies is twofold:
For eliciting requirements that the project result should satisfy.
For validating project results with respect to the requirements from 1.
We have chosen case studies that differ in profile, abstraction, size and application area.
Specifically we have chosen an academic case study of a trading system for handling sales in supermarkets [1,2]; a case study of the Virtual Office of the Future  for supporting seamless execution of office tasks independent of the office workers’ physical location, and an industrial case study on Fredhopper’s server-based software systems  providing search and merchandising IT services to e-Commerce companies.
In Task 5.1 we elicited requirements representative to the theoretical and practical challenges that the envisioned method has to solve. We described the selected requirements in form of detailed scenarios. The result of this task is deliverable report D5.1 .
In Task 5.2 we tested the expressive power of the ABS language and HATS methodology via the HATS case studies. This task formed the basis for verification of Milestone M1. The result of this task is deliverable report D5.2  and a set of formal models of case studies constructed during evaluation .
In this task we applied the modeling techniques developed in WP1, WP2 and WP3 to the artifacts of the various case studies. This task formed the basis for verification of Milestone M2. The result of this task is deliverable report D5.3.
 A. Rausch, R. Reussner, R. Mirandola, and F. Plasil, editors. The Common Component Modeling Example: Comparing Software Component Models [result from the Dagstuhl research seminar for CoCoME, August 1-3, 2007], volume 5153 of LNCS. Springer, 2008. Preliminary version of the chapter describing the Trading System is available at: http://agrausch.informatik.uni-kl.de/CoCoME/downloads/documentation/coco….
 The CoCoME Website, July 2009. http://www.cocome.org.
 Research Highlight: Virtual Office of the Future. http://www.iese.fraunhofer.de/research/vof/vof.jsp.
 Fredhopper Product. http://www.fredhopper.com.
 Requirement Elicitation, August 2009. Deliverable 5.1 of project FP7-231620 (HATS), available at http://www.hats-project.eu/sites/default/files/Deliverable51_rev2.pdf
 Evaluation of the Core Framework, August 2010. Deliverable 5.2 of project FP7-231620 (HATS), available at http://www.hats-project.eu/sites/default/files/Deliverable52.pdf
 Supplementary models of D5.2, August 2010, available at http://www.hats-project.eu/sites/default/files/Deliverable5.2Models.zip