Types of Flexible Manufacturing System Layouts
Reconfigurable Manufacturing Systems
Yoram Koren first came up with the idea of Reconfigurable Manufacturing Systems in 1995. Instead of having each type of machine in a row to handle a part from start to finish, reconfigurable manufacturing systems have rows of each type of machine. After a part has been processed by the first type of machine, it is forwarded to the next available machine in the next row.
Reconfigurable manufacturing systems rely heavily on Computerized Numerical Control orCNC machines and parallel rows of manufacturing centers to produce a product. Reconfigurable systems suffer less disruption if one machine is down, since parts can be easily routed to the surrounding machines.
Reconfigurable manufacturing systems or RMS are designed to handle a mix of products of varying volumes. When demand for product A is low, product B can be produced on the line as well, keeping the factory busy and income flowing.
Several different product flows can run simultaneously on several reconfigurable manufacturing systems if computer aided manufacturing system tracks each part and ensures that the correct manufacturing processes are run on each part and to prevent missed steps. Companies that have implemented RMS include aerospace manufacturers, power train builders and machine tool manufacturers.
Flexible Manufacturing Systems
Flexible manufacturing systems use a combination of machines and parts to produce a wide array of end products. Flexible manufacturing systems or FMS rely on CNC machines, often working in parallel or tandem. Flexibility comes from heavy automation and robotics, but this increases the capital costs of flexible systems. Flexible manufacturing systems are ideal for small and medium sized lots with significant variety.
Theoretically, flexible manufacturing systems can be scaled to a size that rivals the throughput of an assembly line, but it would come with a high initial capital cost. FMS have been used in automotive manufacturers to create mid-sized lots of parts like filter systems and wiring assemblies while retaining the ability to switch to a different product group when the assembly line changes to build a different vehicle.
Flexible manufacturing systems allow companies to build related product lines using the same initial manufacturing processes like metal casting or welding while relying on CNC machines for the final manufacturing steps. The incoming metal blanks are the same, but whether it ends up a license plate or cell phone back depends on the program the CNC machine runs through.
Flexible Assembly Systems
Flexible assembly systems or FAS rely less upon flexible manufacturing equipment like CNC machines and more upon advanced robotic stations or well trained employees. When humans do the assembly work, they use work stations that can handle many different products.
Whether human or robot, they are supported by a part delivery system that can provide each person everything they need regardless of what they are building. Production planning and production control of in-work products are critical to maintain throughput and productivity in FAS systems.
Just-in-time or JIT manufacturing works well with FAS if there are few delays in part delivery and shipment of assembled components to the warehouse or end customer. A flexible assembly system may have no automation at all except for the production planning system, warehouse management system and part delivery network. Flexible assembly systems are used in diverse areas like customization of personal computers, refurbishing cell phones and assembling made-to-order toy kits.
Flexible assembly areas are used to add customization to a mass produced product. They are also used in small operations to support multiple assembly lines when the product mix is always changing.
Rapid Prototyping Machines
Rapid prototyping machines based on 3-D printers are not yet practical for very large or extremely complex assemblies. They rely upon 3-D models from computer aided design software to tell it where to apply each layer of plastic or harden gel into a solid material using a laser.
Rapid prototyping machines have been likened to replicators, though they cannot yet shape metal into intricate shapes, though replicas of marble statues, skulls, plastic parts and geometric designs are now done regularly. Rapid prototyping machines are very flexible but are used primarily for single pieces or a few prototypes. 3-D printing can create complex curves and open geometries that are very difficult and time consuming to create via machining.
Rapid prototyping machines have been described as the pre-cursor to the replicator. Create a design on the computer, send it to the prototyping machine, and watch it spend a few hours making what you’ve requested. While rapid prototyping machines cannot recreate natural materials like wood or yet fashion metal, advances in polymer technologies mean that they can create working parts such as valves, toys and antenna housings.