Performance modelisation and evaluation of MMS services

The manufacturing message specification (MMS) is an application layer protocol (ISO IS 9506) which specifies services for distributed manufacturing applications design. It enables communication between heterogeneous devices. An important topic in application design process is the performance issues, because some applications present performance constraints such as maximal service response time. This paper presents some performance models for evaluating the MMS response time by taking into account among others the real characteristics of a MAP/MMS implementation. Colored stochastic Petri nets formalism was used for models representation on the one hand and simulation for their resolution on the other hand. This choice has been established following the analysis of characteristics of MMS. We have built our models in a progressive way until we obtained the global MMS model. The major problem posed in this work, is the lower layers´ model parameters. These parameters are mainly probability distributions of processing time for each network layer. These distributions are different and specific to each implementation. Their determination is necessary for the quantitative validation of the models. However these indices are inaccessible in the used implementation. To show the behavior of our models, we have therefore put forward hypotheses on the various missing indices