Scheduling is among the most complex operation in the manufacturing module. That is why you need to be well acquainted with the problem and be aware of the solution capabilities offered bythe application.
Let us first take a look at a typical schedule of operation at resurce:
Time schedule displays cycle time, that is, the intermediate time between the start of the first and second operation. Becuase, it should be noted, that in practical use problems occurring when operations do not follow each other smoothly are most difficullt to solve. There are examples when you can execure more than one operation simultaneously, overlapping each other or following each other in consecutive order.
Let us take a look at different kinds of delaying:
I
| Smultaneously
| It starts simultaneously with the previous operation.
|
Z
| Completed
| It starts after the previous operation has completed.
|
O
| Optimum
| It starts after the optimum quantity gets created in the previous operation.
|
This way we included all possibilities of calculating cycle time. Your planning department should decide which option to use. It is wise to combine all of them. This way you can use method I in production where operations follow each other. Some operations can only be executed after all items in production have finished (e.g. thermically processed series). Proceed by using type Z. The most complex method is method O - by optimum quantity.
Let us take a look at them individually:
Simultaneously to previous
Here it is not required to enter any special data becaue it ignores them. Here set-up time not production time are not used. The same holds good for intermediate time. Below you can see the delay chart:
After completed previous
Below you can see the chart:
It starts after the optimum quantity gets created in the previous operation.
It is one of the most interestign types. And at the same time highly complex to perform checks, Let us take a look at the following example. Let us take a PINION for the basis which should be completed on 20th January 1996. To make things simpler all capacities are available 8 hours daily. There is not intermediate time and no set-up time. Manufacture 10000 pieces of the selected subassembly. The optimum quantity is set to 1000 pieces.
The schedule for individual operation is the same as in the previous example.
Because schedules are calculated from the finished product stage back to basic semi-finished products or subassemblies, the operations need to be planned from top down. To illustrate the case it will be enough to use the last three operations:
Operation
| Operation description
| Tsu
| Tpr
| Volume
| Total time
| Optimum time
|
-
| WASH and OIL UP
| 0,000
| 0,025
| -
| 2,5
| 0,25
|
-
| APPLY CORD
| 0,000
| 0,701
| -
| 70,1
| 7,01
|
-
| GRIND
| 0,000
| 1,013
| -
| 101,3
| 10,13
|
Total time is calculated in the following way Tsu + (Tpr * 10 volumne * 10000), Optimum time is on the other hand calculated like this Tsu + (Tpr * 10 volume * 1000).
Manufacturing Scheduling
See tjhe chart below:
It should be noted that overlapping is peformed virtually because what it means is that work order containing a quantity of 10000 pieces is dismantled to ten subordinate work orders containing 1000 pieces each.