Types of Manufacturing Systems
The three main types of manufacturing systems are small batch, large batch and continuous manufacturing.
With the rise of automation and computer aided manufacturing, agile manufacturing and mass customization manufacturing systems have also come into use, attempting to blend the low costs of large batch manufacturing with the responsiveness to customer demands offered by small batch manufacturing.
Small Batch Manufacturing
Small batch manufacturing systems include job shops, machine shops and prototype shops. The manufacturer has many different tools available to complete any combination of required steps to create a single or a few of each product. Small batch manufacturing flows tend to bounce the part between work stations as it is built.
Small batch manufacturing systems have a higher per-unit cost than large batch systems, but offer flexibility and the ability to produce small and medium sized lots that large batch manufacturers may refuse. The latest innovation in small batch manufacturing is the 3-D printer, capable of creating three dimensional models and parts from a computer model. Each model may be a unique prototype or a one of a kind item that would take hundreds of hours to craft by hand.
The classic example of large batch manufacturing systems is the assembly line. Each tool or machine is placed in a location where it can quickly process and forward parts to the next machine or worker. The emphasis of large batch manufacturing systems is on speed in order to produce as much as possible.
Large batch manufacturing systems tend to follow a line or direct flow between machines. This minimizes travel time between stations and reduces the risk of damage during handling. Large batch manufacturing systems tend to be optimized for one particular product. Switching between products has higher tooling costs and down time compared to small batch manufacturing systems. Large batch processing offers lower costs per unit when large volumes, typically thousands of units or more, are produced.
Continuous manufacturing systems or continuous flow systems do not create discrete lots like small batch and large batch manufacturing systems. Continuous manufacturing systems create a continual flow of product. Oil refineries are a classic example of continuous manufacturing systems. You can produce a fraction of a gallon of oil or kerosene, but a widget is either complete or partially done.
Continuous manufacturing includes chemical production, metal refining and plastics extrusion. As long as raw feed stocks are supplied and pumps or motors are running, continuous flow manufacturing systems will keep running. Continuous flow manufacturing offers low costs per unit such as per pound or per gallon.
Agile manufacturing is an attempt to blend the flexibility of small batch manufacturing with the lower unit cost of large batch manufacturing. Instead of one long production line, rows of the same machine are aligned. Blanks or raw materials start at one end and wind between work stations until a finished product comes off the other end.
In another model, computerized numeric control or CNC machines perform multiple manufacturing operations on one blank. Multiple cutting, drilling and welding operations are done by one machine work station. The part would then be removed and be sent for further processing or inspection. Agile manufacturing allows for faster turnover between products than re-tooling an entire production line, but generally requires greater capital investment in CNC machines or multiple sets of tools.
Mass customization is a hybridization of small batch and large batch manufacturing to create custom, individualized products. In some cases, mass produced parts are assembled into unique assemblies requested by users.
Modern fast food restaurants are a service based example of mass customization. Rolls and buns are mass produced and shipped to the restaurant. Vegetables are sent to the restaurant and prepared for use. Meat is cooked according to corporate standards. Then each burger or meal is assembled to order. Customized cell phones and personal computers assembled into custom order units are examples of this.
In other cases, mass-produced semi-finished assemblies are customized to create personalized units. Mass-produced baby dolls that are hand painted with the desired skin, hair and eye coloring are another example. Minor investments of human customization or the addition of accessories from a warehouse create a custom product for a slightly higher cost than the mass-produced item, still relying upon a mass-production manufacturing for the majority of components.