Title: 9.1 Getting Ready for Production
Course: ATEP - MMT: Module A: > Section: GETTING READY FOR PRODUCTION

9.1.1 Methods and Processes

Part of the design phase includes understanding the methods and processes required to produce the product. It is important to know the machines, the method of production and the production procedure.  Review of this knowledge must be considered and re-considered throughout each of the eight design steps.  Module B will help to familiarize the designer with the methods and types of machines currently used in today's world of manufacturing.

Limit the amount of parts:
Helps to keep down manufacturing costs by reducing engineering time, inventory and testing.

Use subassemblies:  (MEDIA ASSETS:  Images of familiar subassemblies(tbd)) Manufacturing and maintenance is simplified and product updates are more easily achieved.

Use "off-the-shelf" parts: (MEDIA ASSETS:  Images of familiar "off-the-shelf" parts(tbd)).  They are less expensive than custom-made components and their reliability are better verified. Standard size fasteners, such as nuts and bolts, are good examples.

Create parts that can be used for different purposes:
A part that can be used in more than one place within the product tends to make assembly easier and cuts down on the end cost.  A company that  manufactures several products can also cut costs by using the same parts in more than one of their products.

Choose the method of assembly that is the most simplistic:
Investigate the different methods to combine the product materials that will help minimize the manufacturing cost.  Avoid using excessive amounts and variation of fasteners as they tend to reduce manufacturing efficiency.

Limit handling:  Minimize the positioning, orienting, and attaching of a part or component. The best method will have all the parts assembled from the top using gravity to assist the assembly process.

Use minimal part specifications:
Excessively close tolerances and surface-finishes are common problems of "over-engineering" that result in higher than necessary production cost.

The cost of the machines, the operating costs and the overhead costs are also factored into the amount that an organization would need to know in order to make a profit.

9.1.2 Quantity Determines Method

Will the product be produced in small or large quantities? Mass production or custom production also dictates the method used for manufacturing. Small quantities of parts might use manual machines or additive manufacturing machines (new technology) while larger quantities might use Computer Numerical Control (CNC) machines, casting or extrusion machines. A great amount of modern day machining uses CNC, in which computers are used to control the movement and operation of the mills, lathes, and other cutting machines.

9.1.3 Conventional & Subtractive Manufacturing

Subtractive manufacturing use traditional machining processes, such as turning, boring, drilling, milling, broaching, sawing, shaping, planning, reaming, and tapping which use machine tools, such as lathes, milling machines and drill presses.

(MEDIA ASSETS 7.C (images/videos of machines (links to Module B).

Other Conventional manufacturing methods are molding, casting and extruding.

(MEDIA ASSETS 7.D images/videos of machines/methods).

Newer technologies such as electrical discharge machining, electrochemical machining, electron beam machining, photochemical machining, hydro cutting, laser cutting and ultrasonic machining are also used in subtractive manufacturing.

MEDIA ASSETS 7.D (images/videos of machines (links to module B)

9.1.4 Additive Manufacturing

As the type and use of additive manufacturing (see table below) continues to become more mainstream, the costs of both the machines and the products they produce will continue to decrease.

9.1.5 Jigs and Fixtures

Part fixtures and jigs are devices that help to align parts to the variety of tools used in the production process.  They reduce the cost of production, help to maintain consistent quality, maximize efficiency and reduce operator errors. During the manufacturing process, parts are often referred to as work pieces.

A jig is a type of custom-made tool used to control the location and/or motion of another tool. A jig's primary purpose is to provide repeatability, accuracy, and interchangeability in the manufacturing of products.

A fixture is a part-holding or support device used in the manufacturing industry.  Fixtures are used to securely position and support a part in a specific location or orientation ensuring that all parts produced using the fixture will maintain conformity and interchangeability. Fixtures decrease the cost of production by allowing a quick transition from part to part.  They also reduce the requirement for skilled labor and increase conformity across a production run by simplifying how parts are mounted.^

  - A jig is often confused with a fixture:
    - A fixture holds the work/part in a fixed location.
      - The tool must move relative to the workpiece;
    - A jig moves the piece while the tool remains stationary.
      - It holds the work/part and guides a tool.

Part of the manufacturing cost will include the number of jigs and fixtures that must be made to assure repeatability for each part.  Tight tolerances in the parts will also require tight tolerances in the jigs and fixtures to obtain that repeatability which is another consideration during the cost analysis.

(MEDIA ASSETS 7.G (Images/animations/Photos/videos)

9.1.6 Number of Steps/Parts Required to Produce the Product

How many steps are involved in creating the product? Can the number of steps be reduced by changing the method or adapting the design to the manufacturing method?

When designing a part, there is always a chance that the accuracy of that part could be compromised during the production process. As the number of parts increase in an assembly, the chance of errors also increase while accuracy decreases. During this step, the design team should review all the parts in an assembly to determine whether components can be eliminated, combined with others or just made simpler which is where the principle of KIS (Keep It Simple) is reviewed. The greater the complexity, the higher the failure rate. Another option is to investigate off-the-shelf parts that might be used to keep the cost down. Standard components will result in reduced non-recurring engineering costs (NRE)." Informed design choices will also lead to optimization and specialization or adaptability and flexibility. Optimization and specialization very often mean a short lifespanm while adaptability and flexibility give the product a long lifespan as it can be used in a variety of other products for different purposes.

(MEDIA ASSETS 7.I )