You ALL know already - the theme of lean is to identify and eliminate waste in the value stream and throughout all parts of the organization.
Usually, the areas that are concentrated upon are on the manufacturing floor. However, many times the wastes found are a result of poor designs. I’m sure that this poor design is not intentional. But it is an indication that the “down stream customer,” whether it’s the internal manufacturing customer or the external end-user, may not have been carefully considered during the design process. So, there has to be a process for the designer to receive feedback early in the design phase, not a year later, after production has already taken place, so that the product is manufactured “right the first time.”
Taiichi Ohno first outlined the concept of the seven wastes almost 50 years ago, recognizing that waste drives up cost. The seven wastes are inherent in ALL processes. In a recent article in Lean Directions, the authors identify how the seven wastes relate to product design. They suggest that in order to design-in lean principles, “designers and engineers must make lean thinking second nature.” They need to essentially “see” the seven wastes on the factory floor for what they are – a result of the product design. Seeing the waste will help them recognize the behaviors and tactics that create the waste.
1. Overproduction – is the “waste of producing a product, service, or information before the customer needs it, or producing more than is needed.” How does design contribute to this waste? By: Expanding the scope of the requirements (adding features that aren’t tied to customer or market requirements)
Including too many options or details on how to test or make the product, dictating the manufacturing process
Creating designs that require batch production; i.e. specialized materials, sole source, high-cost setup, low yield
2. Transportation – is movement of products or materials or information that does not add value. Product design contributes to this waste by:
Not considering how large, heavy, or awkward items will be handled in production
Creating design with multiple parts that could have been simpler
Specifying parts that require purchasing from a great distance away
3. Motion – is movement that doesn’t add value – searching, walking, sorting, bending, etc. Design can contribute to motion waste by:
Not creating “open” designs for easy use, requiring repetitive motion in manufacturing or maintenance.
Creating designs that are not easily oriented for use, maintenance, manufacturing; lack of symmetry requires more motion in production.
4. Waiting – is “idle time in manufacturing created when material, information, people, or equipment is not ready.” Product design can cause waiting downstream by:
Testing and verifying at the wrong level for process feedback and correction.
Delaying production due to incomplete or inaccurate information
“Design programs strive for zero risk and are therefore never quite done for the required schedules.”
Creating designs that don’t anticipate improvements, such as the insertion of technology.
5. Overprocessing – is effort that adds no value from the customer’s view. Analyzing, inspecting, validating, multiple machining or assembly are symptoms of overprocessing waste. The product’s design can generate this waste by:
Creating designs without thought for the production process, attempting to meet “over- specified precision.”
Specifying and requiring source control that add no value and are limiting.
Creating complex designs requiring complex manufacturing processes.
6. Inventory – is more materials or information than is needed to serve the customer right now. Part costs include more than material and labour for manufacturing it. Costs are also associated with material handling and purchasing, data processing, manufacturing engineering, QA, inventory control, warehousing, etc.
7. Defects – are work that contains errors, mistakes, or lacks something. This waste is usually obvious – it requires rework, analysis, problem solving, fighting fires, scrapping. Design has the greatest impact and potential for correction and savings in this area. A badly designed part is one that can be:
has missing design data
requires precision or tight tolerances resulting in low yields
doesn’t meet customer requirements
…resulting in creating waste.