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Process Control and Capability

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  Process Stability Vs Capability Stability means a process is behaving in a predictable way but it doesn't necessarily mean it meets the customer expectations.  Process capability measures to what extent it is able to satisfy the customer requirements. The first step for process improvement is to achieve stability. We analyse this with Statistical Process Control . As a result of this analysis we may find out-of-control situations due to special causes. In this case we need to resolve these causes to make the process stable.  Once the process is stable, we can find out to what extent is it able to meet customer expectations. This is done by measuring   Process Capability . Descriptive Statistics with Excel Download a copy of Excel file   Capability.xlsx   from OneDrive on to your PC to run it. In sheet Diameter  in column A we have 500 measurements of a critical diameter. After being confident that our process is stable we can character...
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Production Scheduling

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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 ...
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