Flexible Process Planning Design and Resource Optimization

Manufacturing processes undergo various transformations based on technological advancements and industry expectations. At initial times, during the period of first Industrial revolution, products were getting manufactured using human capabilities and skills. Then, electrically-driven motors, machines and conveyors were used. Now in the fourth Industrial revolution, Industries are equipped with automation, robots and cyber-physical systems. But adopting such technologies requires a high capital investment which cannot be accommodated by some start-ups. In this research paper, a case of a start-up which manufactures straws and vessel scrubbers in an eco-friendly manner as an initiative towards sustainability has been discussed. The key product of the company is biodegradable straws which are manufactured from coconut leaves through a set of processes. The scope of the research is to develop a labour-intensive process planning model. Managing contemporary issues is a big task for the company because of the dynamic nature of the environment. In this case, the demand for straws changes based on customer preference and accordingly, the manufacturing processes need to be revised. Hence, developing a rigid planning model is not an effective solution, so that, flexible manufacturing process needs to be developed. There is always a scope of improvement towards betterment and optimization in a manufacturing process. It is not necessary that the improvements should lead to drastic results. Japanese manufactures who bring the Toyota Production System (TPS) believe that small improvements in a continual basis will fetch better results in terms of quality, efficiency and lead time reduction. Once the model is developed, areas of improvement to optimize the resources are found out and iterations of process planning model were carried over to improve the efficiency. Through the study, it is found that the development of a flexible process plan is required to compete with the changing business scenarios.

Ant colony optimization approach based on precedence constraint matrix for flexible process planning

An innovative approach integrated into search based on ant colony optimization (ACO) is used to optimize the flexible process planning with the objective of minimizing total weight costs (TWC) against precedence constraints. First, the flexible process planning (FPP) is described as the ordering of the alternative machining operations by decomposing processing operation into several optional machining operations based on different tool access directions, and determining the precedence constraints of the alternative machining operations. Due to the determination of the set of feasible alternative machining operations of processing operation, and the use of the precedence constraint matrix to describe the precedence constraint relationship, the sequence of precedence constraint becomes the limitation of search space for seeking optimal solution. Then, the ant colony algorithm is employed to search the set sequence of the alternative machining operations based on the search space limitation method. Since each ant gets a feasible operation routing, the optimal manufacturing resource of each alternative operation is obtained from the randomly selected manufacturing resource by the minimum cost rule. Finally, compared with the existing genetic algorithm, tabu search, simulated annealing and general ant colony algorithm, the proposed algorithm is proved to be feasibility and competitiveness by instance.