How to use Value Stream Mapping to lean your business Part Two - Over Production
In this eight part series we’ll be taking a look at how Value Stream Mapping can be used to remove waste from your business processes. In part one of the series we took a look at the seven wastes model and in this article we’ll take a look at how VSM can be used to capture over production.
Over-production is simply producing more materials than the customer needs. This can be generated between internal process or processes delivering to external customers.
Over production can be calculated using takt time and inventory levels. Takt time is a common lean concept that simply put is the time allowed to produce a product to meet demand – when combined within a pull system (such as a Kanban) the processes is engineered to produce just as much product that is required by the next part of the production process so that materials are pulled through the system, based on requirement.
Value stream maps can help highlight areas of over production by capturing production time, lead time and inventory data – Analysts can use this captured information to deduce which steps within an activity produce more materials than are required for processing – these steps can then be re-engineered to ensure that production and customer requirements are aligned.