Quiz 10: Quality Management, Statistical Process Control, and Six Sigma Capacity
The type of data that needs to be collected depends on the situation and the problem in hand. Often for defect or defective parts count, the data will be attribute in nature. For other types of situation, the data needs to be in variable form when the outcome can be measured. For control chart, the choice should depend on the what type of output the user wants to monitor. For example, an chart will be used for an output for which the criteria are to monitor or control a measurable parameter or a ratio data. For discrete data, are used for proportion of defectives and defect counts respectively. a. Note the following table explain the choice of data for each of the four situations. b. Note the following table explain the choice of control chart for each of the four situations.
When a portion of output from a process step is reworked, the overall capacity of the step reduces. The reduction of capacity of a bottleneck resource causes the reduction of the overall process capacity. For an unlimited demand scenario, this will result in lower throughput. a. Work is being released at a rate of 5 units per hour. Operation 1 Processing time is 6 minutes per unit. Rework rate is 20% Rework processing time per unit is 15 minutes. So, out of the 5 units, number of reworks generated = So, So, OperatioN2 Processing time is 5 minutes per unit. Rework rate is 10% Rework processing time per unit is 10 minutes So, out of the 5 units, number of reworks generated = So, So, Operation 3 Processing time is 4 minutes per unit. Rework rate is 10% Rework processing time per unit is 5 minutes So, out of the 5 units, number of reworks generated = So, So, Note that all the three operations are having capacity more than the release rate. So, the release rate of 5 units per hour will be the flow rate. So, the utilization operatioN2 is b. The lowest capacity step is Operation 1 with capacity of 6.67 units per hour. So, the bottleneck is c. The processing capacity is the minimum of demand (i.e. the release rate) and capacity of the bottleneck (i.e. operation 1). So, So, the present capacity of the process is . If the release rate is not a constraint and can be increased as required, the process capacity will be the capacity of the bottleneck i.e.