Algorithm of determining Product's Batch Size and Sequence of the Operations of n Job on m Machine

Subject Areas : Futurology

رسول Haji ¹ ( ندارد )
هوشنگ Taghizadeh ² ( ندارد )

Received: 2015-01-13 Accepted : 2015-01-13 Published : 2005-06-22

Keywords: Sequence of Operations, Scheduling, Batch Size, makespan, Setup time, Idle Time,

Abstract :

In this paper, a heuristic algorithm has been presented with the aim of determining the quantity ofa best batch size for minimizing the makespan of a production system in order to meet the demandsof a specified period for a product. This algorithm calculates the time required for fulfilling each ofthe requisite operations for producing a batch size by taking into account the standard time forfulfilling the operations, number of similar parts used in one unit of a product, the machinery setuptime, scrap percentage of each operation on the relevant machinery and the quantity of that batchsize. This algorithm allots the requisite operations to the machinery for producing the total demandof a specified period by making use of the calculated information, SPT1 rule, the specifiedconditions in the algorithm and the quantity of the production in each batch size. Then, with respectto the quantity of this batch size, the aggregate of the setup and idle times of machinery iscalculated for the whole period. Afterwards, the quantity of the optimum batch size whichminimizes the aggregate of these times is obtained by calculating the aggregate of these times forthe different quantities of the batch sizes and comparing them. Some examples have been presentedfor comparing this algorithm with Ho & Chang, Johnson, and Palmer's algorithms. The results showthat this algorithm presents a better makespan in comparison with the aforementioned algorithms.