Centerlining
Assembly Line
How To Centerline A Process
Centerlining, known as Operation Envelopes in some industries, is a philosophy or methodology that utilizes established process settings to ensure a consistent manufacturing process. These process settings often consist of ranges, with upper and lower limits, to allow for flexibility to deal with outside influences (for example, to account for the changes that occur as certain components age or wear). While the original purpose may have been to ensure consistent product quality, several other purposes have evolved, including operating equipment within design limits or safety limits, ensuring adequate cooling or lubrication, and many others. In this blog we’ll use the term Centerline, but whether this term is well known to you, if you call them Operation Envelopes or something else, the concepts and information applies.
To “centerline” a process, you must perform these four steps:
- Identify the important process factors or variables.
- Determine the best settings and ranges for all of the important variables – by grade or product if multiple products are being produced
- Determine how these variables affect the process and the product
- Ensure that the centerlined settings are always used during production