Subcontracting integration in a joint maintenance/production policy: study on profitability conditions

In this paper, we propose to discuss profitability conditions of a subcontracting constraint for subcontractor companies. The subcontracting imposes unavailability periods of the production unit in order to periodically perform subcontracting tasks (ST). We study the subcontracting constraint under a joint maintenance and production approach of a production system composed of one machine M subject to random failures. This machine supplies a constant demand d via a buffer stock S. At each interval T, the machine is subject to preventive maintenance action. The corrective and preventive maintenance actions have random durations. We analytically show conditions under which subcontracting is profitable, based on a given strategies of maintenance, production control and assignment to subcontracting. In this paper, we study the profitability of two cases of subcontracting constraint: occasional and long-term relationship. In the first case, we integrate the ST in the subcontractor plan without changing the decision variables values (maintenance interval and buffer stock size). The second case imposes a new optimisation of decision variables. [Received: 1 December 2008; Revised: 1 June 2009, 18 March 2010, 4 February 2010, 31 May 2010; Accepted: 2 June 2010]