In future manufacturing environment, assembly work will be routinely characterized by shorter production cycles and constantly diminishing lot sizes, while the variety of product types and models continues to increase. Constant pressure to shorten lead times will add to these demands makes the mix truly challenging, even for the most innovative of manufacturers. The ability to respond quickly to rapidly changing customer demands will require the use of manufacturing systems that can be re-configured and expanded on the fly, and which can accommodate advances in assembly techniques without making any initial manufacturing investments.
Lean manufacturing, an approach that depends greatly on flexibility and workplace organization, is an excellent starting point for companies wanting to take a fresh look at their current manufacturing methods. Lean techniques are also worthy of investigation because they eliminate large capital outlays for dedicated machinery until automation becomes absolutely necessary. Indeed, the concept of lean manufacturing represents a significant departure from the automated factory so popular in recent years. The “less is better” approach to manufacturing leads to a vastly simplified, remarkably uncluttered environment that is carefully tuned to the manufacturer’s demands. Products are manufactured one at a time in response to the customer’s requirements rather than batch manufactured for stock. The goal is to produce only the quantity needed and no more. And since limited numbers of parts are produced, it may be necessary to change processes during the day-to-day process. The flexibility in manual assembly cells is therefore preferable to automated assembly. This requirement for maximum flexibility creates unique demands on the lean work cell and the components that make up the lean work cell. Granted, the lean approach is not the solution for all manufacturing problems. But it does offer a uniquely flexible solution for assembling more complex products. This section will describe basic lean manufacturing principles that should help evaluate lean manufacturing solutions for our future applications.
5S
The 5S System, or simply 5S, is a Japanese philosophy that promotes cleanliness and orderliness to achieve maximum productivity and quality. 5S is used by industrial plants and manufacturers, service providers, restaurants, educational institutions, government agencies, and the list goes on. This structured system is generally the first step toward implementing all other lean manufacturing techniques. 5S is not a form of standardized clean up, but a methodology used by many large companies. It endorses continual organization and efficiency in a workplace with an emphasis on waste elimination and visual communication. 5S stems from five Japanese words: Seiri, Seiton, Seiso, Seiketsu, and Shitsuke. Loosely translated, they are sort, set in order, shine, standardize, and sustain. These words represent a five-step concept to reduce waste, streamline operations, and ultimately increase efficiency and productivity. Through a simple five-step process, 5S can increase productivity and worker safety while decreasing waste. The principle aim of a 5S system is improved safety, efficiency, and employee morale. By deciding what should be kept, where it should be kept, and how it should be kept, 5S eliminates wasteful clutter and creates ownership of processes among workers. The results of 5s are both visually and economically dramatic. 5S relies on training, communication, and visual cues such as the use of color coding, labels and signs, and consistent storage locations for tools and supplies.
Continuous Flow
The preferred shape of the lean work cell is U-shaped. Each sub process is connected to the next in order of process. With the worker in the interior of the U, minimum movement is required to move the work piece or assembly from one workstation to the next. Ultimately, one of the goals of the lean