Question 2 of 7: Design for Manufacturing, Lean, and Kaizen

Question 2: Design for Manufacturing, Lean, and Kaizen (20 marks: 7/7/6)

Question text not reproduced: the examination questions are © Engineers and Geoscientists BC. Open the official past paper (linked at the top of this page) to read the question, then follow the worked solution below.

(i) Proactive Design for Manufacturing (DFM)

• Meaning — manufacturing requirements are considered at the design stage, by a team that includes manufacturing engineers, rather than reactively redesigning after production problems appear. Since most of a product's cost is committed at design, this is where cost, quality and lead time are best controlled.
• Typical DFM/DFA guidelines — minimize the number of parts; use standard components and materials; design modular and multifunctional parts; reduce fasteners and use self-locating features; specify tolerances no tighter than function requires; design for simple, one-direction assembly and error-proofing (poka-yoke); match the design to available process capability.
• Benefits — lower cost, fewer engineering changes, higher quality and reliability, faster time to market.
• Manufacturing functions — product and process design; process planning; production planning, scheduling and control; purchasing and materials management (inventory); fabrication/machining and assembly; materials handling; quality assurance and inspection; plant maintenance; packaging, warehousing and shipping.

(ii) Lean — Areas to Study for Zero Waste

The goal is to eliminate the seven wastes — overproduction, waiting, transportation, over-processing, inventory, unnecessary motion and defects. Areas to study:

• Value stream / process flow — map material and information flow to separate value-adding from non-value-adding steps.
• Plant layout — reduce transport and motion (cellular and flow layouts).
• Inventory and production control — work-in-process and finished goods; move to just-in-time pull systems (kanban) and small lot sizes.
• Setup and changeover — reduce setup times (SMED) so small batches are economic.
• Quality — quality at the source, error-proofing and statistical process control to eliminate defects and rework.
• Equipment maintenance — total productive maintenance to eliminate breakdowns and waiting.
• Workplace organization and standard work — 5S, standardized procedures.
• Workforce — cross-training, empowerment and employee involvement.
• Suppliers and product design — reliable, frequent supplier deliveries and designs with fewer, standard parts.

(iii) Implementing Kaizen (Continuous Improvement)

• Management commitment — leaders sponsor the program, provide time and resources, and make improvement part of everyone's job.
• Train and involve everyone — teach basic problem-solving tools; form small cross-functional teams; set up an employee suggestion system.
• Go to the gemba — observe the actual workplace and select a specific problem or process with measurable goals.
• Follow the PDCA cycle — Plan (analyze the current state and root causes), Do (try the change on a small scale), Check (measure results), Act (adopt and standardize, or try again).
• Small, low-cost, incremental changes rather than large capital projects; kaizen events for focused rapid improvement.
• Standardize and sustain — document the new standard work, use visual controls and 5S, audit regularly.
• Recognize and repeat — celebrate contributions and start the next cycle, so continuous improvement becomes the culture.