Engineering & Purchasing: Joined at the Hip

In an industry where engineering is constantly feeding new products to the manufacturing floor, several disciplines must be in place to assure the smoothest transitions from the R&D group to the operations group.

While New Product Introductions (NPI) and associated processes are key to managing lowest costs and highest quality products from introduction to obsolescence there are two specific departments that “travel” with the product throughout its lifecycle. These two departments or functions are Purchasing and Component Engineering.

After a product is released, design engineers, sustaining engineers, manufacturing engineers, test and process engineers are ready on-call for any production or design anomaly that deviates from the expected manufacturing plan, but no two departments stay closer to a product than materials (procurement and inventory management) and component engineering (CE).

Purchasing and component engineering are responsible for the supply chain integrity that guarantees a steady flow of qualified parts and materials required to build and support any product that has been released for mass production. In some companies, the R&D group have their own purchasing staff who buy for pre-release requirements, but in most companies, there exists a single purchasing group responsible for both small pre-production buys and high volume requirements.

One of the reasons the CE is onboard is to help purchasing with not just emergency shortage substitution selection and qualification, but also to thicken or deepen the purchasing buying options by adding equivalent parts to the Item Master list via the Approved Vendors List (AVL) or Approved Manufacturer List (AML) prior to there being an emergency parts shortage.

Purchasing is not generally considered a “technical” discipline in that most materials personnel are not component specifications savvy where they can determine the component’s suitability for a particular circuit design. Rather, their function is to source and purchase components by part numbers that have been pre-approved and listed on the Item Master as qualified for use on specific Bill of Materials (BOM). The Component Engineer becomes purchasing’s best friend as it is the CE’s responsibility to respond rapidly with an alternate source or newly qualified part substitution before there is a line-down situation on the factory floor.

For this reason, CEs are frequently in the “fire-fighting” mode and loving or hating every minute of it. If the CE loves his or her discipline, then the adrenaline rush and rapid learning curve are the stuff of life that makes the job always exciting and challenging. If the CE hates fighting fires, then the job stress will quickly lead to burn out. A CE’s support of purchasing is not limited to background support. Purchasing and CE are connected at the hip and any company that does not have a full-time component engineer supporting purchasing is playing a very dangerous game for two reasons:

First, Original Component Manufacturers (OCMs) and distributors want to push their products to as many buyers as possible. Hence, they may claim their parts are perfect substitutes for the original but if purchasing is not on their skeptical toes, they may buy a part of “similar” function that may be unsuitable for the product being built. Second, only a thorough examination of a prospective component’s specifications, followed by qualifying via physical testing, will guarantee the suitability of the part for substitution.

Too often, manufacturer’s reported specifications that are recorded on datasheets are either insufficient or incorrect. Sometimes, important data like operating environment maximum ratings are “cut and pasted” from a manufacturer’s similarly processed part. It is only when parts are run under actual, expected or worst case, operating conditions that a proposed part for substitution may prove itself unworthy.

Here is a quick example. While working as a CE at Microsoft Corp. we needed a conductive heat sinking gasket between a very hot part and the enclosure. The temperature rating of the gasket material was shown as adequate on the datasheet, but when tested in a product, the gasket became brittle and broke into a thousand bits. These small grains contaminated the test circuit board and because the material was conductive, could have resulted in electrical shorts across the production circuit board.

Why was the datasheet not enough? The gasket material in the manufacturer’s specification was not under pressure during their testing and qualification processes. Our application was also weight bearing, compressing the material and changing the thermal response characteristic of the raw materials used in the fabrication of the gasket.

Purchasing cannot test every part they are going to buy. It is the component engineer’s job to ABOSLUTELY GUARANTEE that purchasing buys only the components that were either specified by the original design engineer, or the alternate parts qualified by the component engineer.

When a product hits the manufacturing floor, there should be NO surprises. Mass production, by definition, is a highly repeatable series of processes and materials that lead to 100 percent predictable results. That is to say, a high quality and consistently performing product operating within the original design specification margins and with the least amount of variances from lot-to-lot bearing the same revision control number.

Only then can the warranties that accompany the products be guaranteed to not exceed the companies’ warranty set-aside cost allotment. Even of greater significance, it assures a company does not lose future or repeat business as a result of poor product performance or quality.

Douglas Alexander has been working in the electronics R&D and manufacturing sectors for over 30 years. He developed and managed several departments at Digital Microwave Corp. (DMC), including Purchasing, Contract Management, Component Engineering, Documentation Control, Contract Manufacturing, and Prototype Assembly Operations. He also worked at Microsoft Corp.'s WebTV division as the founding manager of its Component Engineering department. He recently served at Transparent Video Systems as the Director of Engineering Operations and Logistics.