What is a Flow Manufacturing Process Design?
With Flow Manufacturing, work is defined by the calculated Takt time for each production process. Takt time defines work to be performed by people or machines in a flow process. As a simple example, if we build 24 bicycles a day and work 8 hours a day, we have to build 3 bicycles per hour or 1 every 20 minutes. That 20 minutes is the Takt time for the final assembly process to produce the bicycles. However, the bicycle has a front and rear wheel. Therefore, the process that makes wheels must produce 2 wheels in the 20-minute Takt time of the final assembly process. The wheel process would have a 10-minute Takt time target and it would feed into the final assembly which has a 20-minute Takt time target. The machine that makes the spokes for the wheels, must make twenty spokes for each wheel, so it would have a 30 second targeted Takt time to make each spoke. Once the operations are designed, they are balanced for multiple machines, multiple shifts, etc. That gives you a simple example to understand Takt time.
Takt time defines work in a flow process. In Flow manufacturing, the bill material is basically a flat pile of parts to produce a product. Kanban is used to pull parts into the production process and back from the supply chain. Kanban replenishes material as it is consumed, therefore leaving the observers and philosophers to brand it as just-in-time inventory. Schedule/batch production uses a critical bill of material to pick kits of parts to build sub-assemblies and fabricated items. There is no logical or necessary reason to schedule and pick kits in a flow process.
In schedule/batch manufacturing, production is planned and controlled by building sub-assemblies, fabricated parts and final products that are all defined by a hierarchical bill of material. The bill of material defines what raw parts go into each sub-assembly and fabricated part. The corresponding exploded drawings show how the parts are to be put together or machined.
Flow Design Vs Scheduled/Batch Production
Flow takes production and material pull systems to a mathematical foundation which can be applied to any industry or volume. The Toyota Production System and Demand Flow Technology are based on this methodology. Production operations are balanced together into a mixed-model pull process. PPM Quality is designed into each step and external inspection is greatly reduced or eliminated.
Management commitment is essential to any transformation from batch/scheduling to Flow. They need to make sure all team members understand that Flow manufacturing excellence is not an option.
Using the DFT Technology to design the pull production is the next step. Immediately followed by the Kanban Pull for the material & supply chain. Critical steps on the competitive path.
Process Perfection, Kaizen, Six Sigma, Lean, Waste Elimination…continuous improvement can be achieved in many ways once a Flow Foundation is established.
Flow Manufacturing Strategically
The Flow Manufacturing foundation is built on a responsive Flow production pull process with in-process quality designed into every operation. Material is pulled into production as well as from the supply chain and all scheduling is eliminated.
Double-digit inventory turns and PPM quality will far offset cheaper offshore labor costs. Strategically, the responsive flow manufacturer will make it harder for offshore companies to compete without massive and expensive finished goods.
Inventory is most flexible and least expensive at the raw stage. It is most expensive and least flexible at the finished goods stage. Tearing apart obsolete finished goods to salvage parts should never happen again.
Initially, the focus is on manufacturing. The design of the pull technology eliminates the need for tracking and production scheduling. It will quickly expand to the pull supply chain, support organizations, and cost systems.
Any Model, Any Volume, Any Day
John R. Costanza, the “Father of Demand Flow Business Strategy”
Fabricated parts or assemblies are pulled through production as their consuming part or assembly requires them. Products go through the Flow process in minutes and hours of work content time, instead of the days and weeks it takes using the scheduling (push) methodology. Material is pulled internally to the plant and expanded to the supply chain. The ERP system is used to forecast long term supplier requirements with flexibility pull triggers in a short time period. The outdated ERP system is unnecessary in the production execution and there is not a direct tie between the Demand-Driven Flow production and the supply chain forecasts. Double digit inventory turns are common and expected.