Quality in Assembly: Medical Device Assembler Gets Lean, Improves Quality
January 25, 2008
When physicians need to see hidden problems inside the human body, they turn to computerized tomography (CT) and magnetic resonance imaging (MRI). When medical device manufacturer Medrad Inc. needed to unlock hidden potential in its assembly lines, it got lean.
The company’s assembly plant in O’Hara Township, PA, makes electronic fluid delivery systems that enhance the performance of cardiovascular, CT and MRI procedures. Dubbed the Heilman Center, the plant also assembles coils, probes and other accessories for use with MRI. This high-mix, low-volume operation operates five days per week with one shift of 176 employees.
Prior to opening the center in 2002, Medrad assembled those products in three facilities. Through value-stream mapping, engineers arranged and rearranged lines and equipment with a goal of maximizing efficiency, eliminating waste and optimizing space utilization. Today, the facility is arranged in a series of cells. “Cellular manufacturing allowed us to put more lines in a smaller footprint,” says Mike Kochis, plant manager.
Knowing they’d be shuffling equipment, Medrad’s engineers designed the plant’s electrical and compressed air systems for maximum flexibility. “We can move things around without having to make substantial infrastructure changes,” says Doug Wilson, plant engineering manager.
Flow racks, carts and similar items are custom-built in-house from flexible structural components supplied by Creform Corp. (Greer, SC). For example, electrical test equipment was once housed on shelving in a fixed location, which made testing final assemblies a batch-and-queue process. To solve the problem, engineers custom-built a mobile test platform that can be moved anywhere it’s needed. Similarly, products built in very low volumes-two or three per month-are assembled at a special multiproduct cell. Instead of staging parts and materials for these myriad products at the cell, components are pulled from a central location and kitted on custom-built carts, which are then wheeled into position in the cell.
“With Creform, we can build anything we need, anytime we want,” says Wilson.
Medrad’s lean initiative has yielded significant results. Since 2003, revenue has grown 15 percent annually. Output per employee has increased 20 percent; floor space per unit has decreased by 50 percent; and overall productivity has increased by 30 percent. Since it converted to a demand-pull parts replenishment system, the plant has saved more than $2 million in inventory.
Assembly errors have decreased by 35 percent. That’s no small feat, considering some of Medrad’s products have 200 to 300 components. Color-coded, visual work instructions are a key part of that success.
“In the past, we worked off assembly drawings,” explains Matt Boyle, quality assurance manager for the plant. “They have lines showing where each part goes, but they don’t tell you what steps to take. Without a significant amount of training and [experience building a particular unit], it would be difficult to build a product the first time around.”
Printed on standard paper and organized into booklets, the new instructions illustrate the assembly process step by step. Each page contains a list and images of the parts to be assembled at a particular step, as well as a picture of how the assembled parts should look. The latter also helps a subsequent assembler check the previous assembler’s work. Intuitive icons prompt assemblers to take certain actions. For instance, an eye with an arrow reminds an assembler to “inspect this area.” A nozzle tells an assembler where to dispense dots of adhesive.
“Our goal was to make assembling the product as easy as assembling a bookshelf,” says Boyle.
Medrad’s lean efforts have paid off in other ways, too. Over the past few years, the company has garnered an impressive array of awards. In 2000, it was named one of the 100 best places to work in Pennsylvania. In 2003, it was one of just seven organizations-and the only manufacturer-to win the Malcolm Baldrige National Quality Award. More recently, the Heilman Center was named one of Industry Week magazine’s “Best Plants” for 2007.