Modeling product-mix planning for batches of melt under multiple objectives in a small scale iron foundry

Product-mix of castings of different types/sizes can be produced in a heat (batch of melt) if all these castings require similar raw material composition. However, inappropriate product-mix may lead to under utilization of furnace capacity or failure in timely delivery or overproduction of castings or may call for deployment of excess resources for packing of molds to enable starting of the pouring operation in time. Some objectives, again, can be conflicting in nature. This paper presents a weighted integer goal programming model for the product-mix planning, developed in the context of a small scale iron foundry. Implementation of the model is illustrated using real life data from an Indian foundry.