Batchsize Vs Feedingcosts

Assignment LCM - batchsize vs feedingcosts

Production lines organized according to the lean principles use small batchsizes. This is done to reduce leadtime of the process and create flexibility. The most extreme example of this principle is single piece production. Another principle is the use of JIT (just in time) to feed the production process with materials and components. In the most extreme form every single part is delivered on the place and the moment it is needed for production. Of course this means that many 'milkruns' are needed to feed the production line. For the picking of materials in the warehouse the principle of single piece production means a lot of work.

This raises the question if single piece production doesn't lead to a lot of waste (unnecessary movements/handling) in the feeding process.

Perhaps it is possible to develop a theory that describes the relation between the batchsize and the feeding process. Possible variables in this model are:

- Distance of a milkrun (from warehouse to productionline, dropdistance and back)

- Number of workstations (drop places for the milkrun)

- Batchsize

- Picktime per item

- Takt time

- Etc.

In order to understand the relation between the variables it is useful to construct (draw) a lay-out of a production line. In this layout you have to position an assembly line with a number of workstation. Than position the warehouse. Now the routing of the millruns can be established. To simplify the model assume that the number of parts needed for the assembly is a fixed number (f.e. 5 parts for 1 product at every workstation. So a line with 4 workstations needs 20 parts/product. If single piece production and feeding is used a takttime of 1 minute means 60 milkruns/hour with 20 parts/milkrun). Use Euro 25,-/hour to translate time into costs.

Now keep all variables but 1 constant and see how the behavior of the line is influenced by the changing value of 1 variable. Use simulation (excel or other) to see what happens.

Products to deliver.

- A model (mathematical/simulation) that describes the relation between changing batchsizes and changing feeder activities. The model has to be able to demonstrate the consequences (time/money) of changing values of the variables.

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