Supply Chain : Quality Control in Industrial Engineering
When it comes to the industrial engineering aspect of supply chain management, quality control and quality assurance are two duties that must be undertaken. The former refers to the process whereby measures are taken to make sure defective products and services are not produced, and that the product design meets the quality standards set out at the outset of the project. The latter, quality assurance, entails overlooking all aspects, including design, production, development, service, installation, as well as documentation. Quality control is the field that ensures it gets done right the first time around.
The basic goal of quality control is to ensure that a product that works perfectly is the product that comes off the assembly line. Indeed, quality should not cost anything extra. In the long run, the faster you get it right, the more money the business will save.
The two main focuses of quality control efforts in the commercial sector include reducing the mechanical precision that is required to obtain quality performance, as well as controlling all aspects of the manufacturing operation to make sure that every part of the assembly remains within a specified zone of tolerance.
One of the methods industrial engineers utilize to test the quality of the product is statistical process control, whereby a random fraction of the output is subjected to sampling and testing measures. Since it would take way too much time to test the entire output, this is a time and cost effective means of evaluation. (This is also useful in cases where testing a product effectively destroys it – such as lighting matches.)
If it is necessary to test the whole product, industrial engineers might wish to use the so called “shake and bake” method. In this process, the product will be mounted on to a shake table in an environmental oven. The product is then used and operated on under increasing temperatures, humidity, and vibration until it stops working. This gives engineers clues in to many unprecedented flaws in the particular product.
A similar process is to operate several samples of the product until they break down. This data helps drive improvements in engineering and manufacturing. Oftentimes, minor disadvantages can be discovered, and thus corrected, saving the firm a lot of money in the long run. Sometimes only minor changes, such as adding mold resistant paint, need to be made.
Sometimes, a product will be found to have unnecessary parts. By re-designing these parts with the help of an industrial engineer, the production costs can be lowered the profits increased to a significant degree.
One example is Russian liquid fuel rocket motors. These motors are designed to allow for ugly welding. They will also eliminate grinding and complete operations that do not allow for better motor functionality. There are also some Japanese disc brakes that have an easy to meet precision, with parts that have been tolerance to three millimeters.
Quite often, car makers have programs that are meant to reduce the amount and type of fasteners in the product. These programs reduce the costs of assembly, as well as inventory and tooling.
Another producibility technique employed by many industrial engineers is near net shape forming. By employing a premium forming process, a company can eliminate a ton of low precision drilling and machining steps. Tons of high quality parts can be produced quickly via precision transfer stamping from rolls of generic aluminum and steel. Die casting can be used to make metal parts out of aluminum. Another power technique is plastic injection molding.
When a computer has been incorporated in to a particular product, the product will have many parts with software that fit in to a single light weight part or micro controller. As computers continue to get faster, a lot of times digital signal processing software will be deemed fit to replace the previous analog electronic circuits.
Motion Economy and Human Factors
Among other things, industrial engineering also takes note of how the workers at a factory are doing their jobs. Effectively, this helps them determine how long it should take to perform a specific job. It also helps them determine how to save time in the event that fewer workers could perform a job at the same rate or faster.
Frank and Lillian Gilbreth as well as Frederick Winslow Taylor pioneered the field of motion economy. The latter attempted to understand what it was that cause coal mine workers to get tired, as well as methods that more productivity might be extracted from the workers without forcing them to work longer hours. The Gilbreths, whose efforts were documented in the book Cheaper by the Dozen, figured out a system for categorizing all movements that they called therbligs.
The American Society of Mechanical Engineers further developed this system of therbligs in to five symbols that stand for such movements as delay, inspection, transport, storage, and operation.
Quite often, an industrial engineer will conduct a study based on the time it takes to do a certain task, or take samples of the work in order to understand what exactly the workers are doing. Such systems as the Maynard Operation Sequence Technique have been developed in order to aid industrial engineers in this process.
Many industrial engineers also receive training in the fields of ergonomics and human factors in order to contribute in a broader way to the design of work methods. Thus, they will often conduct time and motion studies.