Control Plans

A control plan is a quality tool, highlighting key product specifications and how/where they will be confirmed before deeming a product good to ship to a customer or the next downstream step.

You’ll put quality checkpoints into your Value Stream, and similar to any manufacturing process these checks will include any instructions, specifications, test procedures, and required tooling for success. These steps are generally “Non Value-Added but Necessary” activities, and so you should aim to do them as quickly as possible - within takt time - while still ensuring that the process is in control and only shipping good products downstream to customers.

There are various ways to implement a quality control plan, and there is no one-size-fits all. Some control plans require 100% inspection for high-value components or products, others may do an audit of parts in each batch of units, and others may rely on continuous data collection and statistical process control to flag when defects are being created.

When starting a new product, it’s a good idea to plan on doing 100% inspection of all key specifications, setting up tooling and processes to execute them efficiently. As you scale, you should be building more consistency into your product Value Stream, and you’ll learn what parts of the control plan are good candidates to wind down from 100% inspection to more automated, less labor-intensive processes. In doing so, you need to be sure to ask yourself “Is the customer still being protected from poor quality with this change?” The target is not just to remove quality inspection points, but to set up your process where you are building quality in to each step, minimizing and mistake-proofing opportunities for error, and then to have the lightest level of inspection possible while still ensuring sufficient quality control.

Additionally, a Failure Mode and Effect Analysis (FMEA) can be a helpful analytical tool to understand what types of controls will be necessary in various parts of the Value Stream.