Chapter 4 Process Design Flashcards
The design of products/services
The design of products/services and processes are interrelated and should be treated together
The overlap of activities
In manufacturing operations overlapping the activities of
product and process designis beneficial.
In most service operations, the overlap between service and process design is implicit in the nature of service. (Haarschnitt: Service = Prozess )
The impact of performance objectives on design (Typical process design objectives)
- Quality: Provide appropriate resources, capable of achieving the specification of product of services Error-free processing
- Speed: Minimum throughput time Output rate appropriate for demand
-Dependability: Provide dependable process resources
Reliable process output timing and volume
-Flexibility: Provide resources with an appropriate range of capabilities. Change easily between processing states (what, how or how much is being processed?)
-Cost Appropriate capacity to meet demand Eliminate process waste in terms of, · excess capacity · excess process capability · in-process delays · in-process errors · inappropriate process inputs
The impact of performance objectives on design (Some benefits of good process design)
Quality: Products and service produced ‘on-specification’ Less recycling and wasted effort within the process
Speed: Short customer waiting time, Low in-process inventory
Dependability: On-time deliveries of products and services. Less disruption, confusion and rescheduling within the process
Flexibility: Ability to process a wide range of products and services. Low cost/fast product and service change.
Low cost/fast volume and timing changes. Ability to cope with unexpected events (e.g. supply or a processing failure)
Cost: Low processing costs. Low resource costs (capital costs)Low delay/inventory costs (working capital costs)
Manufacturing process types
Project processes (Variety: High, Volume: Low) -Build Aircraft, Nuclear Powerplant, BER.
One-off, complex, large scale, high work content
‘products’. Specially made, ‘every one customized’. Defined start and finish: time, quality and cost
objectives.Many different skills have to becoordinated.
Jobbing processes (Variety: Higher, Volume: Lower) -Carpenter, architects.
Very small quantities: ‘one-offs’, or only a few required.
Specially made. High variety, low repetition. ‘Strangers
every one customized’. Skill requirements are usually very broad. Skilled jobber, or team, complete whole product.
Batch processes: (Variety: Intermediate, Volume: Intermediate) -
Higher volumes and lower variety than for jobbing.
Standard products, repeating demand. But can make
specials.Specialized, narrower skills. Set-ups (changeovers) at each stage of production.
Mass processes: (Variety: Lower, Volume: Higher)
Higher volumes than batch. Standard, repeat products (‘runners’). No set-ups or almost instantaneous ones.
Low and/or narrow skills
Continuous processes: (Variety: Low, Volume: High)
Extremely high volumes and low variety: often single
product. Standard, repeat products (‘runners’). Highly capital-intensive and automated. Few changeovers required. Difficult and expensive to start and stop the process.
Service process types
Professional Service (Variety: High, Volume: Low)>Lawyer
High levels of customer (client) contact.
Clients spend a considerable time in the service process.
High levels of customization with service processes being highly adaptable. Contact staff are given high levels of discretion in servicing customers. People-based rather than equipment-based.
Service shop (Variety: Intermediate, Volume: Intermediate) > Car repair Medium levels of volumes of customers. Medium, or mixed, levels of customer contact. Medium, or mixed, levels of customization. Medium, or mixed, levels of staff discretion.
Mass service ( Variety: Low, Volume: High) Callcenter, Public transportation High levels of volumes of customers. Low to medium levels of customer contact. Low, or mixed, levels of customization. Low, or mixed, levels of staff discretion.
Throughput efficiency
Throughput efficiency =
Work content/Throughput time × 100
Little’s law
Throughput (TH) = Work-in-progress (WIP) × Cycle time (CT)
