Polyhedrika

  Value streams require real time data collection in order to control them. This is often done automatically by the equipment itself but in some occasions it must be done manually.  In spite of the high-tech of our shop floors you can still see pencil and paper data collection being used. https://youtu.be/C7chwW_cXbc Unfortunately, detecting aspect defects is often difficult to automate even with AOI (Automatic Optical Inspection). When an operator is required to inspect we need a method to enter the results into the system. Line incidents, change of critical process parameters, etc. also need to be reported the moment they take place. Pencil & Paper Reporting The method still widely used in this 21st century is: The operator hand writes the defect data on a form Forms are collected at the end of the shift A clerk types the forms contents into the system at a later stage The engineer analyses the results and takes corrective actions well after the data was entered. This reporti

  The first step for process improvement is 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. We need to resolve these causes to make the process stable.  Stability means the process is behaving in a predictable way but it doesn't necessarily mean it meets the customer expectations.  To find out to what extent is the process able to meet the customer expectations we measure 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  we have placed in column A our data consisting of 500 measurements of a critical diameter. After being confident that our process is stable we can characterize it with descriptive statistics in Excel Data Analysis:   These are the results: basic statistics of our data  Frequency Distribution Histogram The histogram gives a graphical representation of