Stellar Auto JIT Case Writeup

Operations Management Course

Answer 1:
Manufacturing System for ISD – To Assemble cockpit Sub-Assembly
Following is the distribution of activities across three workstations that we are proposing to be laid out at ISD. This distribution is designed in order to maintain consistence Takt time of 8 min at both ISD and SAL. This will ensure that the output rate at ISD matches with consumption rate at SAL FAA line.
Workstation 1 finishes its task after step 9, and workstation 2 finishes its task after step 23. At both these steps 9 & 23, description says that ‘rotate the sub assembly such that the front end is facing the operator’ which validates that WIP sub assembly can be handed over to succeeding work station. Refer to Exhibit 1 in the annexures.
As per this design the cycle time of process is 8 minutes, because station 1 has a maximum of 8 minutes takt time and that becomes the bottleneck station.

Flow Diagram
Trolley Capacity Calculations:
The model variant information is provided by SAL after the body comes out of the paint shop.Cockpit sub-assembly for a particular model variant need to be made available when that Body reaches at station 9, allowing 64mins of time margin. (8 stations*8min takt time) for ISD to assemble and deliver cockpit sub-assembly for that model.
As per the data provided in the case 1. Total activity time at ISD each sub-assembly will take 23.85 minutes to finish the operations (calculated from Exhibit 4 in the case). 2. Transit time from ISD to SAL is 16 mins one way.
Therefore ISD can deliver a particular sub assembly in minimum 39.85 minutes to SAL at station 9, after they receive information from SAL.
Trolley size - 2
If there is constraint on storage of only one sub-assembly along the line side at SAL workstation 9, then it restricts the batch size of shipping from ISD to