Explaining the Non-compliance between Templates and Agreement Offers in WS-Agreement

A common approach to the process of reaching agreements is the publication of templates that guide parties to create agreement offers that are then sent for approval to the template publisher. In such scenario, a common issue the template publisher must address is to check whether the agreement offer received is compliant or not with the template. Furthermore, in the latter case, an automated explanation of the reasons of such non-compliance is very appealing. Unfortunately, although there are proposals that deal with checking the compliance, the problem of providing an automated explanation to the non-compliance has not yet been studied in this context. In tins paper, we take a subset of the WS-Agreement recommendation as a starting point and we provide a rigorous definition of the explanation for the non-compliance between templates and agreement offers. Furthermore, we propose the use of constraint satisfaction problem (CSP) solvers to implement it and provide a proof-of-concept implementation. The advantage of using CSPs is that it allows expressive service level objectives inside SLAs.