Machining A systems approach

Ref: Chen, Joseph (2001). Educational Factory - From Design to Manufacturing Overview. Iowa State University Manufacturing System

Manufacturing Cost

DFM A basic understanding of Design for Manufacturability, DFM, makes you a more effective manager (ITEC) and/or teacher (TechEd) by understanding the interaction of [a] machining operation(s) within the context of material processing with respect to COST, QUALITY, and PRODUCTIVITY!

3 mechanisms toward DFM 1.Design-manufacturing Teams 2.Common CAD systems for design & tooling 3.Understanding the value concepts

Training Needs Comparison of Industry and Academic Perspectives on the Training Needs of the U.S. Manufacturing Workforce (Prziembel, 1995).

Value Engineering THE VALUE OF A PRODUCT IS THE RATIO OF ITS PERFORMANCE TO ITS COST Obtaining the maximum performance per unit cost is the basic objective of value engineering (Gage, 1967; Mudge, 1971)

Economic Perspective The “Economic” Perspective on Value Creation For any product, a “value equation” can be defined... Non-reoccurring Cost allocation Indirect labor costs Direct labor costs Direct material cost Profit per unit - $$ PRICE or VALUE Determined by Customer

Value Analysis Value analysis (VA) programs, as generally conducted today (Bradyhouse, 1984), first challenge the design of the product - searching for simpler designs that will reduce cost while maintaining function.

A simple example 2 parts1 part Screw – $ 0.02 Washer - $ units = $.03 * 100 = $ seconds/screw = 5 * 100 = 500 seconds (8.33 min) 2 seconds/washer = 2 * 100 = 200 seconds (3.33 min) ( )*($0.25) = $ 2.92 ($ 3.00) + ($ 2.92) = $ 5.92 Screw – $ units = $.02 * 100 = $ seconds/screw = 5 * 100 = 500 seconds (8.33 min) (8.33)*($0.25)= $ 2.08 ($ 2.00) + ($ 2.08) = $ 4.08 Material Cost Labor Cost Material Cost Material + Labor = Cost Labor Cost

Cost Comparison $5.92 $4.08 =.69 ~ 30% cost reduction with new design OLD 2 part Design NEW 1 part Design

The other side Manufacturing Engineering –Concerned with assuring that parts can be manufactured and assemblies made and tested to meet specifications with available or potentially available techniques, tooling, and test equipment at cost compatible with the product’s selling price (Howell, 1982). –The emphasis in manufacturing engineering is to protect the interests of the manufacturing function

VA/Mfg. Engr. Relationship - Before

Product Development- Review Traditional: Sequential Product Development Aka: “Throw it over the wall” MARKETING RESEARCH & DEVELOPMENT ENGINEERINGMANUFACTURING Voice of the Customer/ Market Opportunity Satisfaction of Customer’s Needs

Concurrent Product Design Satisfaction of Customer’s Needs

Design for Manufacturing (DFM) Needed Concept decisions, product design, and testing are performed prior to: –Manufacturing system design –Process planning and production TEAM approach is the KEY for success

2 Main streams of DFM Design for Machining (DFM)Design for Machining (DFM) is designing products with machining in mind. Design for Assembly (DFA)Design for Assembly (DFA) is designing products with minimum assembly cost in mind

Design For Machining Goals of Design For Machining 1.Reduce machining time 2.Reduce material costs 3.Reduce tooling costs 4.Reduce setup cost VALUE Eventually increase VALUE of a product

Examples of design concepts using Design For Machining

Limit Tooling Bad Design – 2 different techniques required Better Design – profiles similar

Radius Corners of Pockets Extremely difficult, if not impossible to machine Better Design

Chucking Surface Better Design: Area for clamping Poor Design: No place for clamping

Restricted Surfaces Better Design: Both areas now accessible Poor Design: No access

Single Plane Clamping Surfaces Better Design: 3 surfaces for clamping Poor Design: Awkward and time- consuming for clamping

Design For Assembly Texas Instrument Example

Design For Assembly

Comparison - DFA Original Design Redesign DFA Improvement (%) Assembly Time (h) Num. of Different Parts Total Num. of Parts Total Num. of Operations Metal Fabrication Time (h) Total Weight (lb.)

vs. Comparison - DFA

TEAMWORK Concurrent Product Design: Include ALL members

Team Makeup Basic understanding of teamwork in work force environment Decision making techniques, ie. Brainstorming, etc Project management skills Communication skills Problem resolution technique

Flowcharting

Gantt Charting

Communication Skills in Teams 1.Listening skills: hearing and comprehending what is said as opposed to waiting for one team member to stop talking 2.Dialoguing skills: interacting for the purpose of increasing mutual discussion 3.Consensus building: synergizing, building new understanding as opposed to compromise which is “both team members giving something up” to arrive at a solution

Characteristics of effective teams T hey produce results P urpose of the team is clear and takes priority over personal agendas M embers feel invested in success and accountable for the outcome P eople are clear on their roles and assignments N othing is under the table T eam members are not afraid to surface a problem T rust, collaboration, and candid discussion are evident T he team does not lose sight of its goal

Attributes of good team members They have strong, shared values They overcome obstacles and handicaps They incorporate and represent diverse backgrounds They are protective and supportive of one another There is a submission of self for the good of the team

CAD Systems

Spatial Skills

REVIEW Who casts the biggest shadow in terms of cost % in manufacturing? Product Design Explain how Design For Manufacturing is an integral part of the product design cycle?

Review How can we add value to a product? Reduce: Machine Time, material costs, tooling costs, & setup costs Of the 3 communications skills, which do you feel you can work on to improve ? Why? Listening, dialoguing, consensus