In order to answer the question “what is Continuous Flow?” we first need to know what flow is.
Flow is the movement of a product or service through the process which creates it.
Thus we can then define Continuous Flow as:
The progressive performance of tasks along the value stream so that a product or service proceeds from start to consumption without stoppages, or back flows.
Therefore the goal for an organization implementing Continuous Flow is to get all there processes arranged and designed in such a manner that once work starts on a product or service that work continues without stopping to completion.
This is not an easy to achieve goal, especially in an existing facility which has one or monument processes or machines in place. In these situations it is often best to create smoother flow after the monument, and utilize minimum batch size up to the monument, along with a supermarket just after it. This tactic will need to be maintained until it is economically viable to eliminate the monument.
In order to be able to create Continuous Flow and organization, must understand the need and benefits of Flow to their operations. After that they will need to be able to implement several other concepts or tools the first of these often include the following:
- Value Stream Mapping
- Heijunka or Level Production
- One Piece Flow over batching
- SMED (Single Minute Exchange of Dies) or Quick Changeover
- TPM (Total Productive Maintenance)
- 5S Organization
- Visual Factory Management
- Seven Waste Elimination
- Standardized Wok
- Proper Cell Layout
- A Kanban Pull System
- Just in Time
- Poka Yoke or Error Proofing
These tools and concepts along with many others will help an organization first create flow and eventually help it achieve Continuous Flow in its operations. They do so by eliminating the impediments to flow the main ones are listed here:
- Fluctuations in Demand
- Unforeseen Problems (Breakdowns, Delivery Failures)
- Poor Process Control
- Limited Process Capability
- Long Setup or Changeover Times
- Product or Service Variation
- Monument Equipment; multiple parts off one machine or process that requires long setup or changeover time
- Excess Part Handling and Transportation Time
- Excess Inventory Especially Buffer Stocks
Overtime a Lean organization will eliminate these impediments one by one, thus improving the flow of their operations, until they achieve a state of Continuous Flow. But like everything Lean even attaining Continuous Flow, is not an end, but just one part of a never ending journey to improve and increase value created, and to reduce and eliminate waste.
What is Continuous Flow?
Well the answer is simply any process that can be made to flow without interruption from start to finish on customer demand.