MODELING AND ANALYSIS OF REPAIRABLE EQUIPMENT MAINTENANCE CONTRACTS INVOLVING THREE PARTIES- MANUFACTURERS, AGENTS AND CONSUMERS

• Main Author: Faizatus Sa'idah, Nur
• Format: Dissertations
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/70994
• Institution: Institut Teknologi Bandung

Heavy equipment is a repairable equipment used in two main activities of the coal mining business namely the process of loading and hauling. Some types of heavy equipment used include dump trucks, excavators, etc. If the equipment is failured, the company accept losses. To maintain the availability of heavy equipment, coal mining companies tend to subcontract maintenance actions to Original Equipment Manufacturing (OEM, hereinafter referred to as the manufacturer) or agent. Subcontracting by the company to the manufacturer/agent is done within the framework of the maintenance contract. The research to be undertaken considers that the maintenance contract selected by the company should contain complete maintenance actions, including Preventive Maintenance (PP) and Corrective Maintenance (PK) for [0, L] ie throughout the life of the machine. The maintenance contracts offered by the manufacturer / agent may take the form of a 1D contract (with a time limit, eg a 1-year contract) and later may use 2D contracts (with time limits and use, e.g. 1 year and/or 100,000 km contract). PK actions carried out warranty period can only be performed by the manufacturer because they are included in the warranty package. Unlike the PP actions in the time range [0, W], this action can be done by both the manufacturer and the agent. After the warranty period ends until the machine lifetime ends in the range [W, L], the PP and PK actions are the responsibility of the coal company that is met by selecting the maintenance contract offer from the manufacturer and/or agent. The formulation of the effect of PP actions can be in the form of reduction in (i) failure intensity function and (ii) virtual age. The first novelty in the research conducted was to formulate the effect of the PP's actions by considering the machine's reliability and availability. Two maintenance contract models that will be developed in this study are 1D maintenance contracts with imperfect PP with the influence of reducing (i) the failure intensity function and (ii) the effect of virtual age reduction. Two advanced models are the formulation of 2D maintenance contracts with imperfect PP with the influence of reducing (i) the failure intensity function and (ii) the effect of virtual age reduction. Decision problems for the three parties involved are modeled with game theory formulations. Decision model optimization to get optimal decisions involve optimizing 2 (two) levels. At the first level optimization involves the manufacturer and agent, and at the second level optimization involves the agent and the consumer. In addition, for each level, the optimization function includes the objective function and the constraint function of mix-integer non-linear types. This type of optimization problem can not be solved by analytical method, but with the approach of numerical method and heuristic method. We will use some evolutionary algorithm approach and develop in search of best possible solution. This is expected to be the second novelty to be done in this study. This study considers that the position of manufacturers and agents is not equal (in the sense of relationships with each other in the form of hierarchy), as well as coal mining companies that act as consumers. The three-party relationship pattern involved is formulated with a two-level optimization approach and game theory. The first level of optimization is the optimization of decisions taken between manufacturers and agents. The second level of optimization is the optimization of decisions taken between agents and consumers. At the first level, the manufacturer occupies the position of leader (leader) in decision making while the agent occupies the position of follower (follower) for the manufacturer. The relationship between the manufacturer and the agent can cooperate or compete in carrying out maintenance which includes the actions of PP and PK. At the second level, the agent occupies the position of leader (leader) for consumers who act as followers (followers). This research developed the Esmaeili model from non-repairabel products to repairable products. Thus, the development of the model needs to involve Preventive Maintenance (PP) because the product is repairable. A Genetic Algorithm (GA) approach will be developed to find the optimal decision in the case of a maintenance contract.