7.3 Introduction

Producibility is an engineering function directed toward achieving a design which is compatible with the realities of the manufacturing capability of the defense industrial base. More specifically, producibility is a measure of the relative ease of producing a product at the desired rate and with acceptable yields, quality, reliability, cost and performance. Producibility is a coordinated effort by design engineering, manufacturing engineering, and other functional specialists to create a functional design that can be easily and economically manufactured. The product must be designed in such a manner that manufacturing methods and processes have flexibility in producing the product at the lowest cost without sacrificing function, performance, or quality.

The A-10 program office along with their contractor, Fairchild Republic, conducted producibility engineering activities (Figure 7-2) which resulted in:

Figure 7-2 A-10 Aircraft

• An airframe that was 95 percent aluminum by weight;
• Rivets that were required to be flush on only the forward section of the aircraft;
• The only compound curvature was of the tub and nacelles;
• Landing gear pods that were external which simplified the load paths and internal structure;
• There was a heavy use of extruded parts which helped to minimize machining requirements;
• Empennage components were standardized so that there were no left-hand or right-hand parts

DOD policy on major system acquisitions makes producibility considerations a requirement prior to the start of Technology Development. The Alternative Systems Review should have included producibility assessments of the design concepts. Producibility assessments and engineering should be a part of the on-going systems engineering process. DODI 5000.02 states that "design for producibility" shall be a part of the Engineering and Manufacturing Development phase. DODD 5000.01 states that the PM shall "reduce manufacturing risk and demonstrate producibility" prior to full-rate production.

History has demonstrated that as the complexity of systems increases, so does the acquisition cost. Therefore, producibility programs are necessary as a management means for assuring that practicality is addressed and that the cost increases associated with the growing complexity of systems are minimized. It should be recognized that the producibility analysis accomplished by the program management office (PMO) must be performed by a team of specialists assembled from the program office: and supporting organizations. One functional organization cannot possibly accomplish the total producibility effort without assistance from other functional organizations. Consequently, the PMO approach to organizing for producibility is of prime importance to a successful defense system.

Producibility may be defined as the relative ease of production. It is relative because the system may be inherently complex (e.g. a submarine or spacecraft) or it may be difficult to produce because the designers may have little or no education on how to make systems producible. The intelligent government representative recognizes that the contractor may understand the definition of producibility but have no training. Most universities in the US offer little hands-on education with manufacturing processes. The best producibility engineers have "scar tissue" – experience earned the hard way.

Producibility is the degree to which "Design for Manufacturing" concepts have been used to influence system and product design to facilitate timely, affordable, and optimum-quality manufacture, assembly, and delivery of system to the field. Producibility is closely linked to other elements of availability and to costs. Items that feature design for manufacturability are also normally easier to maintain, have better accessibility features, and have lower life cycle costs.

Manufacturability – is the overall ability to consistently produce at the required level of cost and quality. Manufacturability focuses on process capabilities, machine or facility flexibility as considerations in the design cycle.

Causes of poor producibility can be classified as errors of either commission or omission. Errors of commission could include such elements as excessive complexity in the design, production restrictiveness, and conflicting direction. Errors of omission could include such elements as inadequate planning and direction, inadequate specification, and insufficient detail. Designers do not start out their day with the intent of producing a bad design or one that is less than optimal. Often the problem is that the designer lacks experience, that is you have a junior engineer assigned to a position that requires someone with more experience, or the program is on an aggressive schedule that provides little time for producibility engineering activities.

Rube Goldberg was an American engineer and inventor but was most famous for his series of cartoons depicting complex devices that performed simple tasks (Figure 7-3). Most DOD weapon systems are inherently complex. As the design evolves and is iterated to achieve performance objectives, designers need to address the design's complexity, efficiency and producibility. Thus systems engineering needs to emphasize producibility engineering throughout the entire design process in order to achieve an efficient and optimized design. Program managers and engineers should understand that by the time a design is frozen a large percentage (about 80 percent) of the life-cycle cost are locked in. Early producibility will help to ensure that the product is producible, supportable and affordable. Design for Manufacturing and Assembly (DFMA) is one tool that design engineers can use to help simplify the design of their product and achieve higher design efficiency or optimization.

Figure 7- 3 Goldberg Device for Remembering to Mail a Letter

This occurs when items are designed with features that are difficult to manufacture and the design was achieved with little or no manufacturing input as to the producibility of the design. It is important that design and manufacturing engineers work together to understand current manufacturing process capabilities and designing to those capabilities where practical will help you to achieve a robust design.

Often there are conflicting design goals. For example, the warfighter needs you something strong but at the same time needs to reduce the weight. Or the warfighter is operating in a corrosive environment but the product should not use material coatings that could harm the environment.

Two common errors in planning is:

• Not allowing enough time after testing to redesign a product and retest, and
• Not have a truly integrated product team. It is a team on paper, but true interaction is not taking place at the necessary levels.