Quality improvement in a factory

A make-to-order mechanical engineering factory was struggling with the supplier quality. Components were ordered for customer order manufacturing and oftentimes the components were found out to be out of specs – and many times only when the machining or assembly of the components was about to start.

Quality Development
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The consultant joined the team, and the work was decided to start with 5S and visual control principles implementation – the first step in any Lean journey in a factory.

After that, a 3-step process implementation was agreed both in the factory and with the main first tier suppliers:

  1. Critical-to-Qualities. Together with the product management and market/customer understanding it was defined, what characteristics in the product (product-CTQ) define the quality and what they mean to the manufacturing process of the factory (process-CTQ). CTQ’s were implemented on the factory floor as part of visual control principles.
  2. (Statistical) Process Control. At the critical manufacturing process phases, it was defined what are the control limits in that process phase to keep the CTQ’s at all time.
  3. Production Part Approval Process, i.e. Change Control. It was defined what are the pre-requirements that any supplier needs to fulfill before any change (material, method, manpower, etc.) can be approved and how the change approval happens.


Within three months the factory implementations were completed and the implementation focus shifted to first tier suppliers.