Mathematical model for the minimization of the mean disassembly time of a mechanical system at design stage

This article proposes a mathematical model for the optimization of the mean disassembly time of a mechanical system at the design stage. The model takes into account the maintenance budget allocated by the user on a given horizon. Two independent stages are prior to the implementation of the proposed model. At first, the designer defines the types of possible links to achieve each connection between two components of the system. Also, he indicates all possible constraints related to each type of link, such as incompatibility with other types of links. Furthermore, the designer indicates the possible tools which can be used to destroy or replace each connection and the duration associated with the use of a given tool. The second step is the generation of all possible disassembly sequences to extract each component of the system. To do this, we propose an algorithm that explores the transition matrix generated by a disassembly algorithm available in the literature. The proposed model compiles all these information in order to suggest to the designer the type of link to choose for each connection and the appropriate tools which will help to minimize the mean disassembly time of the components during maintenance operations. The suggestions of the model take into account the maintenance budget on a given horizon. The estimated cost of maintenance on the horizon include: the cost of purchasing the equipment, the cost of buying spare parts and wages of the maintenance operators. The model provides other information such as the optimal disassembly sequence of each component and its duration. An illustrative example is provided to validate the consistency of the model.