Lean drives modularity: People & Companies

Lean manufacturing principles have changed the way engineers program machine tools and select tooling. Batch processing of parts, piles of work in process and dedicated fixtures are quickly becoming extinct as companies realize the cost advantages of being lean.

In the not-so-distant past, for example, it was common to build dedicated fixtures for machining a part. Often, a part required multiple fixtures to hold it in various orientations. Having multiple dedicated fixtures for a part increases the development cost and lead time, and dedicated fixtures often go unused or get scrapped when a job becomes obsolete.

Companies that eliminate the waste associated with dedicated fixtures have a competitive advantage in the marketplace. Many companies that embrace lean principles have eliminated dedicated fixtures and switched to modular ones.

Modular fixtures are constructed from a standard set of components that are interchangeable. Often these products are provided in kits of various sizes, which can be expanded by adding components as needed. The components are combined to make a fixture for one part and then disassembled and reassembled in different configurations for other parts.

Unilock 5-axis riser chucks from BIG Kaiser Precision Tooling Inc. come in many different lengths and are available on base plates and as stacking modules to elevate a workpiece off the table for clearance or reach issues during multiple-axis machining. Image courtesy BIG Kaiser Precision Tooling.

There are several benefits associated with modular fixturing, such as reducing the lead time to develop a new part. At the company where I work, Mitsubishi, the delivery of a new assembly fixture can take 12 to 14 weeks after the vendor receives the order. CAD programming and sourcing activities prior to placing the order can add another 12 to 14 weeks, which means it takes 6 to 7 months to complete a dedicated fixture and get it to the machine. Modular fixturing can reduce these times to days, generating huge cost savings. A short lead time for fixturing can also be a game changer when trying to win new work.