Job shop schedsuling using genetic algorithm
Abstract—The job-shop scheduling (JSS) can be difined as a planning of schedules with many variations according to the requirements. In job-shop scheduling problem (JSSP) environment, there are numbers jobs to be processed on numbers of machines with a certain objective function to be minimized or maximized. In this paper, we have used the GT-GA to solve the job shop scheduling to minimize the makespan along with the special type of crossover known as multi-step crossover fusion (MSXF). To see wheather we get good results by modifyinng the classical approach using GA, we have compared the result with the standard benchmark instances available. Using this combinations of the techniques, we have got results showing deviations less than 3%.
Index Terms—Scheduling, Job Shop Scheduling, genetic algorithm.
Introduction:
The job shop scheduling problem is the combinatorial problem in which there can be many objective functions. In this paper we have selected the makespan to be the objective function. The main objective of any scheduling is to create a schedule which specifies when each task is to begin and what resources it will use that satisfies all the constraints while taking as little overall time as possible. The scheduling in which there is a specific order of a job to be processed by perticular machines is called as job-shop scheduling problem. This kind of scheduling and sequecing of operations deals with the allocations of resources optimally over time so as
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Vakharia and Chang (1990) developed a scheduling system based on this method for manufacturing cells. Jeffcoat and Bulfin (1993) applied the same to a resource-constrained scheduling problem. Their results showed that this procedure provided the best results in comparison with other neighborhood search procedures. This method is an iterative search
The JIT approach to manufacturing involves timing the delivery of resources so that they arrive just when needed. Inventory optimization models help the firm determine how many of which items in which sizes should be delivered to each specific store during twice-weekly shipments, ensuring that each store is stocked with just what it needs. Trucks serve destinations that can be reached
The assembly line needs to produce 6 units per hour and there is room for only four workstations. The tasks and the order in which they must be performed are shown in the following table. Tasks cannot be split, and it would be too expensive to duplicate any task.
The JC Gear Company has decided to initiate a project aimed at automating its production planning and control system. Among the options, the company focuses on two alternatives: (1) purchasing the most suitable system off of the shelf and modifying it according to its individual production needs; or (2) developing a system
Akveld, M., & Bernhard, R. (2012). Job shop scheduling with unit length tasks. RAIRO -- Theoretical Informatics & Applications, 46(3), 329-342. Retreived from http://search.ebscohost.com.ezproxy.liberty.edu:2048/login.aspx?direct=true&db=iih&AN=85410818&site=ehost-live&scope=site
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Other assumptions that we made for the case study were that we could only use the 7.5-hour workday and one line of production. We also assumed that we were limited to the range of 8 to 12 people stated in the problem. Because we are making complex equipment, we assumed that we could not change the order of the operations themselves but that we could have a station do varying combinations of operations. The projections in the Excel spreadsheet also assume that the engineers’ specified times would be accurate once production begins. Regarding the hardware testing operations, the activities are to be performed on three computers concurrently, so we divided the operation times by three to arrive at the true operation times.
The idea of applying exact optimisation approach on requirements selection and optimisation is similar with search-based requirements optimisation. The only difference is that, instead of using search-based optimisation algorithm, the search-based requirements selection and optimisation problem is tracked with exact optimisation algorithm. There are three main categories exact optimisations found in the literature. They are Integer linear programming [25], dynamic programming [26], and exhaustive search [27].
A brief description of a job shop scheduling problem has already been provided in Chapter 1. In this project, the size of the considered problem is J×M, where J represents the number of jobs (5) and M represents the number of machines (5). Four rules will be tested on a data set consists of twenty case
During the recent past period, academic researchers and practitioners devoted their efforts for improving the scheduling process and developing an effective approach. They were seeking to optimize scheduling problems through exploration and exploitation the solution space. The first section in this chapter presents two different optimization approaches that are able to solve and optimize job shop scheduling problem. The first type of optimization approaches is based on exact algorithms and they are usually used for simple and small size problem. Another type of approaches is based on more sophisticated algorithms that can be applied to more complex and larger problems. These approaches are denoted as approximate algorithms where the solutions may be optimal or near-optimal. Approximate algorithms can be classified into heuristic and meta-heuristic methods. The main purpose of this chapter is to present a comprehensive survey of different approaches available for solving the job-shop scheduling problem. It will be important also to identify the trend of research and the gaps that require further research in the second section of this chapter Jain and Meeran [12].
−−−Preliminary study of an automotive assembly plant for high volume production(1300cars/day with 2 type of cars, 4 doors and 2 doors respectivly, and flexible in volume, 3 shifts of workers)
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