A Framework For Student Learning In Manufacturing Engineering

The framework proposed in this paper offers a compact outline for transforming traditional process-dominated manufacturing engineering curricula into comprehensive learning in product realization. The outline includes four stages: product engineering; process engineering; quality engineering; production engineering. The paper presents an application of this learning progression that is implemented within a traditional set of courses -an approach that can be adapted and adopted by other faculty virtually instantaneously. Also presented is a suggestion for thorough overhaul of manufacturing engineering curricula into a substantively new format. The paper concludes with observations and measures of student response gathered in application of the four-stage model in the author’s classes. Context and Continuity: As a formal field for academic preparation, the discipline of manufacturing engineering has been evolving for only two or three decades. Through the sponsorship and leadership of the Society of Manufacturing Engineers, documents offering curricular structuring, suggested course content and focused central learning objectives appeared from the mid-1980’s through the 1990’s. 1,2,3 Likewise, over the past ten years, competency maps and gaps for various stages of manufacturing engineering careers have been published by SME and others. 4,5,6 Following a landmark SME publications in 1985 and 1988, 1,7 each of the historical documents has offered guidance for developing curricula and specific course content in an incremental evolution. These recommendations maintained a constant focus on manufacturing engineering as a dominantly process-oriented discipline, enhanced with soft-skills. This paper suggests a more comprehensive framework for the manufacturing engineering discipline encompassing the full spectrum of product realization. The Essence of Manufacturing: The essential nature of manufacturing is the creation of products. Indeed, no products (outside of raw vegetables, perhaps) exist that are not manufactured. Although global information exchange and market competitiveness in all corners of the world are vital and pervasive issues, manufacturing enterprises exist to produce products and to do so in a fashion that generates current and continuing profit. Thus, it is contended that the learning of manufacturing engineering must begin with deep understanding of products of a variety of genres. Subsequent learning about value-added processes for material transformation, quality measurement and management, and design of production systems and enterprises are all, then, accomplished in the context of the creation of products and from the foundation of strong knowledge of materials processing. Despite the plethora of management tools that have flooded the market-place over the past decade or so, manufacturing remains at root a materials processing enterprise. Manufacturing occurs when a material is altered in some way that adds value. 8 The workpiece materials evolve into the product, and the product is the entire purpose of the manufacturing enterprise. The procedures through which the material is altered are what we know as ‘manufacturing P ge 1.44.2 processes’. The requirement that value be added necessarily implies that the altered material is of appropriate quality and worth. The set of activities through which value is added via various stages of processing and to a variety of parts is the production system. It is germane to note that this definition of manufacturing is completely general. Any material to which value is added through application of a process of some kind has been manufactured. This rubric can be as easily applied to production of silicon wafers or cardiovascular stents as to internal combustion engines and automobile bodies. It follows that the principles of manufacturing engineering ought to be applicable as general practice, not prescribed by particular materials, processes or product forms. The Essence of Manufacturing Engineering: All engineers solve problems, and all engineers design things. What differentiates the engineering disciplines is the type of problems addressed and the objects of the design activity. Some engineers design products; some design processes. In the main, manufacturing engineers design processes. However, the purpose of these processes is the production of product. Following the logic of manufacturing traced in the previous paragraph, ‘design’ in manufacturing engineering spans the product realization spectrum. A logical extension to the fundamental definition of manufacturing is to identify sub-disciplines in manufacturing engineering. Product Engineering Process Engineering Quality Engineering Production Engineering Figure 1: Four Sub-disciplines in Manufacturing Engineering These sub-disciplines can be defined a bit more thoroughly. There is a logical path to be followed in the realization of the product. The rubric can be most readily illustrated through the following instructions that are issued to students undertaking a project to design a manufacturing system for a given product. 9 The context is that student teams in a ‘production engineering’ class fulfill the learning objectives for the course through a semester-long project. Student teams design a production system for an existing product. The products have been as varied as cast steel flow control valves, printed circuit boards and fishing reels. Integrated into the fabric of the project, students are challenged to critique the product design to improve manufacturability and reduce cost. The first three stages of the project are reported in progress-report format, and the overall system design is presented in a comprehensive final report. Product Engineering: Develop a complete bill of materials for the product family. Determine a preliminary make-or-buy differentiation for all parts. Document the reasoning underlying these determinations. For the parts selected for purchase from vendors, describe specifications suitable for action by a company purchasing agent. For parts selected for inhouse manufacture, identify the feature characteristics of each part (or family) that determine the manufacturing processes and process parameters to be employed. Assemble the parts to P ge 1.44.3 be produced into groups of similar manufacturing processes. This will look like a table of parts, features, sizes and processes. Process Engineering: Develop process flow mapping to define the manufacturing processing necessary to produce the families of parts. In these maps, identify the specific manufacturing processes to be employed in each stage of material alteration. Devise analytical models for machining each feature, and select the primary process parameters to be used (depth of cut, feed, cutting speed, cutting tool). Compute the necessary values for spindle speed, machine feed, material removal rate and spindle power consumed. Determine the specifications of the machine tools needed (machining envelope, speeds, power, tool capacity and change time). Estimate cycle times for machined parts. Select specific machine tools (make and model, specifications, footprint, operating floor area). Quality Engineering: Identify the specific measurable features that determine ‘quality’ in these products. Define a quality management strategy. Determine what measurements are necessary and when during the production processing the measurements are to be taken. Determine the specifications of the inspection equipment (part capacity, characteristics measured, precision). Select specific inspection apparatus (make and model, specifications, footprint, operating floor area). Production Engineering: Define production strategy (production quantities, shift arrangement, etc.). This will require further research to determine a reasonable annual production quantity for the assigned products. Include in the production strategy, an identification of the quantity of each machine tool and inspection station required. Define material handling and inventory storage methods. Determine staffing requirements. Design a floor plan. Identify bottlenecks and methodology for continuous improvement. Estimate throughput and inventories (raw materials, work-in-progress, finished goods). It is certainly true that manufacturing engineers, in practice, will be called upon to contribute to concurrent engineering product development teams. Successful modern manufacturing stems from iterative and parallel thinking, not serial procedures. Part of the manufacturing engineer’s responsibility lies in influencing product design for designed-in quality and ease of manufacture. Anecdotal evidence strongly indicates that mastering process and production system design through a product-centric lens provides a very strong understanding of such crucial issues as design-for-manufacturing and designing quality into the product. Students who have learned manufacturing engineering through the framework outlined above have been sought after for attractive and competitive career positions, and they report rapid progress in their companies. A Minimalist Application: A course framework for teaching manufacturing engineering in the four sub-disciplines suggested in Figure 1 can be either very compact to fit as a concentration within another major or purposefully designed as the core of a stand-alone major. A minimalist methodology could involve as little as only two purpose-specified courses beyond traditional fundamentals. As such, specialized instruction in manufacturing could be crafted as an option or concentration within mechanical engineering or industrial engineering or agricultural engineering or another major. In this scenario, courses in ‘process engineering’ and P ge 1.44.4 ‘production engineering’ would be comprised of intermediate-level analysis and design, based on a traditional introductory course in ‘manufacturing processes’, such as has been taught for many years on man