How to Use 3P to Work Out Process Design Alternatives

By Jon Miller | Post Date: October 25, 2006 10:18 PM | Comments: 13

Apoorva from India asks, "Generally how many alternatives are worked out in 3P?" Production Preparation Process, or 3P as it is known, is the name used to describe the American consulting market's understanding of the Shingijutsu consulting company's understanding of the Toyota Motor Corporation's approach to process development and production preparation. In a previous post we discussed the 16 catch phrases of 3P which are an embedded thought process for this type of production preparation.

The 3P approach involves identifying "alternatives" or options for performing each transformational step in a process. It requires thinking of a process such as high speed drilling as "make hole" so that the essential function performed is the objective, not the current technology used to make the hole (CNC drill). This is not dissimilar to how VA/VE looks at processes.

When you are designing equipment, or a production line that is built from a series of processes and connected equipment, you need to identify alternatives for each step. This can be tedious. Most engineers who are first faced with 3P balk at this exercise when there is a catalog full of solutions. Generating seven alternatives can be like pulling teeth. Plenty of "stupid ideas" are needed. A cross functional team is definitely recommended.

The short answer to Apoorva's question is that you need to come up with seven alternatives, mock up the top three, and then build the top one selected from evaluation criteria. Why seven? Because that's what the great Nakao sensei, co-founder and head of Shingijutsu tells us. Six is too few, eight is too many, perhaps.

After creating a charter for a 3P project to define the scope and desired outcome, a properly trained production preparation team would use the Process At A Glance to develop seven alternatives, evaluate the seven alternatives to select top three, sketch out model operations on Process At A Glance, simulate the three alternatives as and then select top process design.

The simulation can involve building 3D (three dimensional) mock ups using cardboard, wood, duct tape, etc. to get as close to the concept as possible, quickly. Once the size, shape and functions performed are defined actual functioning models can be built and tested. The more simulation you can do, the closer your models will be to the final item.

The main reasons to start "inside out" from value added transformation or feature creation ("make hole") to the fixture, the controls, the box instead of "outside in" by selecting a machine out of a catalog is that it helps avoid buying or building machines with lots of unnecessary accessories.

The idea of 3P is to build bare bones machine with human wisdom and designed for quick changeovers, pokayoke and one piece flow. This requires thinking through several alternatives and then asking the questions which direct your thinking towards kaizen. The following guidelines can be used for evaluating and ranking the alternatives:

Q-1 Pokayoke is built into the process
Q-2 Go/nogo gauging for in-process checks
Q-3 Fewer than 0.03% defects
Q-4 Auto-stop for abnormality (jidoka)
C-1 Low motion waste
C-2 Low capital investment
C-3 Minimal space required
C-4 Known process technology
C-5 Minimal development time required
C-6 Simpler than existing process methods
C-7 Easy autonomous maintenance, or maintenance free
C-8 High ratio of value added time in the process
C-9 Low tooling cost
D-1 Easily scalable up by 400% or down to 25%
D-2 In-house development
D-3 Off-the shelf equipment or components
S-1 Proper guarding and safety devices in place
S-2 Dust, chips, slag, etc. collected by equipment
S-3 High ergonomics evaluation score
S-4 Meets environmental, fire, and health regulations
L-1 Creates one-piece flow
L-2 Meets Takt Time
L-3 Creates a pull system
L-4 Quick changeover
L-5 Operator input
L-6 Chaku-chaku (load load)
L-7 Hanedashi (auto unload)
L-8 Mobile & flexible, on wheels, not roots or vines

That's how to use 3P to work out process design alternatives. Thanks for the question.

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