Related Literature

There is substantial amount of literature available on Materials Management and MRP in the form of research papers, books and articles in Journals etc. Some important methods are: MRP needs for Make-to-Order Company, J Hoey, B.R. Kilmarting and R.Leonard (1986), Scheduling and order Release, James R. Ashby (1995). For determining the role of inventory safety stock on MRP: Optimal positioning of safety stock in MRP, A.G. Lagodimos and E.J. Anderson (1993), product Structure Complexity W.C. Benton and R. Srivastava (1993).

Yenisey (2006) applied a flow network model and solved a linear programming method for MRP problems that minimized the total cost of the MRP system. Mula et al. (2006) provided a new linear programming model for medium term production planning in a capacity constrained MRP with a multiproduct, multilevel, and multi period production system. Their proposed model comprised three fuzzy sub models with flexibility in the objective function, market demand, and capacity of resources. Wilhelm and Som (1998) present an inventory control approach for an assembly system with several types of components. Their model focuses on a single finished product inventory, so the interdependence between inventory levels of different components is once again neglected. Axsater (2005) considers a multi level assembly system where operation times are independent random variables. The objective is to choose starting times (release dates) for different operations in order to minimize the sum of the expected holding and backlogging costs. Kanet and Sridharan (1998) examined late delivery of raw materials, variations in process lead times, interoperation move times and queue waiting times in MRP controlled manufacturing environment. To model such environment, they represented demand by inter arrival time rather than defined from the master production schedule. Kumar (1989) studies a single period model (one assembly batch) for a multi component assembly system with stochastic component lead times and a fixed assembly due date and quantity. The problem is to determine the timing of each component order so that the total cost composed of the component holding and product tardiness costs is minimized. Chauhan et al. (2009), presents an interesting single period model. Their approach considers a punctual fixed demand for one finished product. Multiple types of components are needed to assemble this product. The objective is to determine the ordering time for each component such as to minimize the sum of expected holding and backlogging cost. Van Donselaar and Gubbels (2002) compare MRP and line requirements planning (LRP) for planning orders. Their research basically focuses on minimizing the system inventory and system nervousness. They also discuss and propose LRP technique to achieve their goals. Minifie and Davies (1990) developed a dynamic MRP controlled manufacturing system simulation model to study the interaction effects of demand and supply uncertainties. These uncertainties were modeled in terms of changes in lot size, timing, planned orders and policy fence on several system performance measures, namely late deliveries, number of setups, ending inventory levels, component shortages and number of exception reports.

Billing ton et al. (1983) suggested a mathematical programming approach for scheduling capacity constrained MRP systems. They propose a discrete time, mixed integer linear programming formulation. In order to reduce the number of variables, and thus the problem size, they introduce the idea of product structure compression.