One of the most important aspects of Lean Manufacturing involves having teams measure their own output and quality. An OEM (original equipment manufacturer) like Henry Ford could easily help their teams identify the pace (takt time) by simply dividing the available time by the demand. An hour by hour chart (linearity chart) for this example would be easy for the team to develop and maintain.
High mix-low volume environments are more challenging. Different products may require significantly different labor content and processing times. A ‘job shop’ linearity chart needs to adjust (and represent) the rate of production based on a variety of speeds. This will result in a linearity chart that looks a bit like a staircase.
OMEP’s hybrid hour by hour chart allows teams to input the number of staff members, organize (and sort) the best possible sequence – producing a chart that provides a clear indication of when capacity is exceeded (loaded hours), along with a time-phased visual indicator of team progress at any moment of the day.
By plotting the ‘actual output’ alongside the expected production output, anyone could walk by and easily recognize whether the team is ‘on track’, over-producing or behind schedule (regardless of the complexity of an individual product type). Teams can record ’causes’ of over/under production directly on the chart, gathering data over time; helping them identify common causes and repeat offenders (e.g.: material shortages or machine breakdowns), in order to identify potential future C.I. projects.