statisticalprocesscontrol(英文版)-文庫吧在線文庫
【正文】 imits determine the difference between random and assignable variation usually ? 3? ? Each new sample statistic is plotted and pared to the control limits UCLLCLUCLL C LUCLL C LStatistical Process Control Types of Control Charts 1. Variable Control charts A. Means Chart monitors central tendency B. Range Chart monitors dispersion both can be used to monitor same process use 20 25 samples to build initial limits take samples of 5 9 observations reasonable amount of time and costs less U CL X A R? ? 2LC L X A R? ? 2U CL D R? 4LC L D R? 3Types of Control Charts (cont) 2. Attributes Control Charts A. PChart count number of defects in sample B. CChart count number of defects per unit building control charts adds to the time and cost of production attribute sampling is easier than variable need larger sample sizes U CL P Z P? ? ??LC L P Z P? ? ??U CL C Z C? ?LC L C Z C? ?Process Capability ? Specify ranges for certain product dimensions during design – Tolerances – Max and min acceptable level of output – Bearing for rotating shaft diameter is inches ? – Process has ? = inches a 3? con
教學課件相關推薦
鄂ICP備17016276號-1