Polyhedrika

SMT Assembly Line   Production Scheduling When we need to process different products in the same line we want to work out the best job sequence to minimize lead time and maximize capacity utilization. We also need to work out the minimum lot size to meet the demand and minimize lead time. Before we can commit the delivery date of a new job to the customer we need to know the status of the jobs already being processed For non repetitive processes you can use project management scheduling The ideal of "Lean Production" is lot size of 1 but this is not always possible when change-over time is significant.  This change-over involves loading different components and changing jigs or molds.  When change over or setup time is significantly higher than process time we are forced to work with larger lot sizes. One way to minimize lot size is to minimize setup time. The SMED (Single Minute Exchange of Dies) methodology has been very successful to reduce setup times from hours to ...

    A still picture of a Value Stream Map may not fully explain the behavior of the Value Stream. In some cases we need to understand its dynamic behavior. To do this we will convert our Excel Value Stream Map into a Monte Carlo Simulator. In Excel Value Stream Map we saw how a complex Value Stream could be mapped using Excel. We saw the importance of mapping feedback loops such as test-repair loops because they may become the bottleneck for the complete value stream. In this situation not all items flow along all branches so we need to calculate the % flowing along each branch. This enabled us to calculate the cycle for each workstation based on the staffing. Finally we were able to calculate the ideal staffing to balance the line: insure no workstation cycle is above the average inter-arrival time (takt time). This we did using Solver. Value Stream Map: Still Picture Vs Dynamic Behavior Mapping the current value stream is a good starting point to understand how it behaves b...