B shop manufacturing schedule after preparing the ms

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(b) Shop Manufacturing Schedule: After preparing the MS, shops schedules (SS) are prepared. It assigns a definite period of time to a particular shop for manufacturing products in required quantity. It shows how many products are to be made, and on what day or week. (c) Backward or Reverse Scheduling: External due date considerations will directly influence activity scheduling in certain structures. The approach adopted in scheduling activities in such cases will often involve a form of reverse scheduling with the use of bar or Gantt charts. A major problem with such reverse or 'due date' scheduling is in estimating the total time to be allowed for each operation, in particular the time to be allowed for waiting or queuing at facilities. Some queuing of jobs (whether items or customers) before facilities is often desirable since, where processing times on facilities are uncertain, high utilization is achieved only by the provision of such queues. Operation times are often available, but queuing times are rarely known initially, the only realistic way in which queuing allowances can be obtained is by experience. Experienced planners will schedule operations, making allowances which they know from past performances to be correct. Such allowances may vary from 50 per cent to 2000 per cent of operation times and can be obtained empirically or by analysis of the progress of previous jobs. It is normally sufficient to obtain and use allowances for groups of similar facilities or for particular departments, since delays depend not so much on the nature of the job, as on the amount of work passing through the departments and the nature of the facilities.
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125 Operations schedules of this type are usually depicted on Gantt or bar charts. The advantage of this type of presentation is that the load on any facility or any department is clear at a glance, and available or spare capacity is easily identified. The major disadvantage is that the dependencies between operations are not shown and, consequently, any readjustment of such schedules necessitates reference back to operation planning documents. Notice that, in scheduling the processing of items, total throughput time can be minimized by the batching of similar items to save set-up time, inspection time, etc. (d) Forward Scheduling: For a manufacturing or supply organization a forward scheduling procedure will in fact be the opposite of that described above. This approach will be particularly relevant where scheduling is undertaken on an internally oriented basis and the objective is to determine the date or times for subsequent activities, given the times loran earlier activity, e.g. a starting time. In the case of supply or transport organizations, the objective will be to schedule forward from a given start date, where that start date will often be the customer due date, e.g. the date at which the customer arrives into the system. In these circumstances, therefore, forward scheduling will be an appropriate method for dealing with externally oriented scheduling activities.
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