A2 Technology

Product Design

Systems and Control Notes

DT4 - Exam

Organising the Manufacturing

7

Coming up in this unit:

• Principles of industrial manufacturing systems which will include:– mass, – batch, – one off; – staffing needs, – allocation of costs, – JIT manufacture and commercial liability; – bought-in, standardized part assembly, – sub-contracting

Mass Production

• Mass production (also called flow production, repetitive flow production, series production, or serial production) is the production of large amounts of standardized products on production lines.

Batch Production

• The primary characteristic of batch production is that all components are completed at a workstation before they move to the next one. Batch production is popular in bakeries and in the manufacture of sports shoes, pharmaceutical ingredients, inks, paints and adhesives.

Batch Production

• Manufacturing station or CELL.– Standard components– Products in– Products out– Power– Testing– Workers seat

Staffing needs

• Workers need :– Training– Paying (even when sick)– Incentives– Contracts of employment– To be flexible– Respond to market

demands– Respond to company

priorities– Job security

• Companies are aware that– Skilled labour costs more– Machines replace work

force and are cheaper in the long run.

– Other countries offer a cheaper labour

– Employment law exists to protect workers’ rights

– They can make workers redundant

Cost Allocation

• A Prices are calculated by …– Materials– Equipment– Labour– Profit– Overheads– Transportation– Marketing

• 4Ps

Just In Time

• The philosophy of JIT manufacturing is to meet consumer orders with a quality product with minimal delay and effective use of resources. The JIT system is sometimes referred to a ‘lean manufacturing’ as it focuses on giving customers value for money by reducing wastage.

Implementing a JIT

• 1) F Design FLOW process– F low Redesign or re-layout for flow – – L Reduce lot sizes (quantities of item)– O Link operations – – W Balance workstation capacity

• M Preventative maintenance.

• S Reduce Setup Times.

Implementing a JIT

• 2) Q Total quality control – C worker compliance– I Automatic inspection– M quality measures– M fail-safe methods

• W Worker participation (suggestion box)

Implementing a JIT

• 3) S Stabilize Schedule– S Level Schedule– W establish freeze windows– UC Underutilize Capacity

• Keep the orders constant and do not try to over produce, similarly leave space for one high demand.

Implementing a JIT

• 4) K Kanban Pull System – D Demand pull– B Backflush– L Reduce lot sizes

• Backflush costing is a method of costing a product after manufacturing has been carried out. Then costs are backflushed through the system to calculate an overall cost for manufacture.

Kanban pull to keep stock up

When red zone reached new products are needed to re-stock a zone.

A card (or any other visual e.g. computer method) is used to identify the items

Implementing a JIT

• 5) V Work with vendors – L Reduce lead time– D Frequent deliveries– U Project usage requirements– Q Quality Expectations

• Lead time is the time it takes from design conception to retail sale.

Implementing a JIT

• 6) I Further reduce inventory in other areas – S Stores– T Transit– C Implement Carrousel to reduce motion

waste– C Implement Conveyor belts to reduce motion

waste

Implementing a JIT

• 7) P Improve Product Design – P Standard Production Configuration– P Standardize and reduce the number of

parts– P Process design with product design– Q Quality Expectations

Implementing a JIT

• In summary– Just in time reduces waste by making to order– Lead times need to be reduced– Emphasis on Lean production– Involvement of all people workers and

vendors– FLOW

Lead times• In Semiconductor Industry• In very complex manufacturing environment, like the manufacture of

microprocessors, a usual Lead Time may be between 5-7 weeks. This is due to the sequence of operations, where there are multiple very similar steps repeated, and none can be skipped. If a manufacture of a CPU requires 35 exposure masks, that translates approximately into 35 x (photoresist coating, exposure, development, main process step (like etching, diffusion, metal filling), photoresist stripping and/or polishing + other possible steps ) plus additional steps before and after all processing. There are wait times not only associated with scheduling a product into production, since the product lines are busy, but also a beginning run of production goes to scrap (plus tool change and alignment takes time), and there are possible wait times of batches being processed during the production. (Not all machinery works at the same speed, or requires maintenance steps, tool change, plus there is the time it takes to physically transport the silicon wafers from one processing machinery to another in small transport batches.)

Lean Manufacturing• Lean manufacturing or lean production, which is often known

simply as "Lean", is the practice of a theory of production that considers the expenditure of resources for any means other than the creation of value for the presumed customer to be wasteful, and thus a target for elimination. In a more basic term, More value with less work.

• Lean manufacturing is a generic process management philosophy derived mostly from the Toyota Production System (TPS) and identified as "Lean" only in the 1990s. It is renowned for its focus on reduction of the original Toyota seven wastes in order to improve overall customer value, but there are varying perspectives on how this is best achieved.

• The steady growth of Toyota, from a small company to the world's largest automaker, has focused attention on how it has achieved this.

Stages in Production

Stages of production.

Stages of Production

Transportation

Labelling

Packaging

Finishing

Assembly

Processing

Storage

ForwardOrdering

BuyingCycle

SourcingMaterials

Stages

Stages of production

1. Sourcing of materials, where, expense, sustainability 2. the buying cycle, when, how often, reliability of supply,3. forward ordering, reduction of lead times, good

supplies, reliability of supplier4. storage, where, wasted space, 5. processing, what method to use? 6. assembly, how, best method?7. finishing, how best method?8. packaging, why? Security? Marketability?9. Labeling, bar coding, kanban10. Transportation, plane, train automobile?

(iv) Detailed manufacturing methods, when preparing, combining, manipulating or processing materials.

• Comparison of hand and commercial methods of – preparing, – shaping, – cutting / wasting, – joining materials, – circuit board production, – population and soldering; – the influence of the above on the time taken to

produce the product, its quality and final cost.

(v) Management systems for production, quality assurance, organisation of equipment and people.

• Internal Quality Control (QC) and external Quality Assurance (QA) requirements;

• project management systems including flow charts, Gantt charts and critical path analysis;

• modern methods of labour organisation to include single craft, progressive bundle and cell.

(vi) Safe working practices, including identifying hazards and making risk assessments.

• Commercial working practices and responsibilities and their application to project work;

• five-step risk assessment. 1. Identify hazard, 2. who might be harmed & how, 3. evaluate potential for risk, 4. record, 5. review if details change;

• provision of equipment, signage etc.;• the safe operation of electrical, mechanical and

pneumatic systems.

Past paper questions