Improving energy efficiency of manufacturing systems through formal analysis of alternative strategies

Energy efficiency is a widely discussed topic in in the manufacturing industry due to environmental and economic reasons. Manufacturers are always looking for being more energy-efficient which is a recipe for being more competitive, reducing waste and spending less money on energy than it is necessary. Potentials to save energy are present at every level and a special attention should be given to unused energy during idle times. Switching systems during these times to energy-efficient modes is one of these potentials that is somehow neglected and not very much explored in the literature in terms of formal models. This problem can be reduced to models exhibiting parallel strategies displaying different timing and energetic profiles and dependability between the different systems; the ultimate goal is to find optimal strategies respecting all the manufacturing-related requirements. The objective of the thesis is to formalize such problems by proposing a methodology directly implementable in the model checker PRISM. This model checker imposes high restrictions on continuous variables used in automata-based models; this makes a discrete approach more appropriate for modeling systems for the purpose of evaluation and optimization. Use-case examples are presented in order to illustrate the approach and explain the extent of what could be done with automata-based models in the model checker PRISM.