Seasonal Trends Analysis with Excel
Process variation analysis is essential in order to improve it. There is always variation. Sometimes we only have random variation such as in the case of dice throwing: https://polyhedrika.blogspot.com/2020/12/dice-throwing-exercise.html Normally we have additional variation caused by special causes and these are the ones we should analyse and reduce first. Hourly Production We are going to analyse the hourly production data collected during one month: Download this Excel file Trend Analysis.xlsx from OneDrive folder Process stability SPC charts allow us to check for stability: see if all variation is random. https://polyhedrika.blogspot.com/2020/12/spc-analysis.html We now apply an individuals SPC chart to our production data to check this: The green and red dots are a clear indication of lack of stability: there are special causes affecting production. Timestamp Data Collection When we collect process data either manually or automatically it is essential to collect the timestam
