Lean Operations

Question 1

Definition (Slack et al 2016)

Answer 1

Lean Operations whilst being a method of operations planning and control, is also considered a philosophy. The principle ethos of lean operations is improvement (in efficiency), typically through small incremental change such as kaizen; which translates to ‘continuous improvement’.

Question 2

Aims of Lean (Slack et al 2016)

Answer 2

To meet demand instantaneously, with perfect quality, no waste and at low cost.

Question 3

Lean Synchronised Flow (Diagram)

Answer 3

Stage A Stage B

Question 4

Lean Capacity Utilisation / Stoppages

Answer 4

Any stoppage will affect the whole lean process, leading to lower capacity utilisation, at least in the short term. Lean operations aim to expose stoppages and ultimately improve or fix them, as opposed to a traditional operational approach which could obscure the problems with for example, high inventory.

Question 5

Lean Operation Management (CADDIE FQ)

Answer 5

Creativity - open idea generation, motivation
Autonomy - direct involvement responsibility
Development - support workers to support business
Discipline - work standards, environment and quality
Involvement - open communication, participation
Equality - open-plan offices, equal pay rates

Flexibility - expansive responsibilities
QWL - security, leisure etc

Question 6

Jidoka/Heijunka/Kanban/Nagare

Answer 6

Jidoka - humanising the interface between operator and machine
Heijunka - levelling and smoothing the flow of items
Kanban - signalling to the preceding process that more parts are needed
Nagare - laying out processes to achieve smoother flow

Question 7

Toyota’s Seven Wastes - Fujio Cho (IMPOT DW)

Answer 7

inventory, motion, processing, overproduction, transportation, defects, waiting time.

Question 8

Causes of Waste (3 M’s)

Answer 8

Muda - activities in the process considered wasteful because they do not add value
Mura - lack of consistency/unevenness
Muri - absurd/unreasonable/overburdening

Question 9

Types of Waste

Answer 9

Inflexible response - large batches, delays between activities
Variability - (inconsistent quality) poor equipment, defects

Question 10

Value Stream Mapping

Answer 10

A.K.A. end-to-end system mapping, a visual map of a product/service production path from start to finish. Typically involved the whole supply chain.

Question 11

Cell-based Layout/Gemba Walk

Answer 11

Aims to bring more systemisation, synchronisation and control to the process flow. Reduces inventory, increases communication and thereby workflow (less time waste). E.g. cell arrangement of U shape.
Gemba Walk - there is no substitute for seeing the processes actually operate in practice - applying cell-based layouts arranged in a U shape allows clear and high levels of visibility throughout the processes.

Question 12

Pull Control

Answer 12

The downstream stage in a process, operation or supply network pull items through the system rather than push them by the supply stage.

Question 13

Kanban Example - Torchbox Digital Product Agency

Answer 13

A large magnetic whiteboard (the Kanban board) tracks completed features through each stage of the design process. When one feature is done, another is pulled through. Only by completing work can you start on something new. Visualisation of the job process identified bottlenecks and/or stoppages to mitigate impact on efficiency.

Question 14

The 5S’s (Gemba Kanri)

Answer 14

Sort - eliminate what is not needed and keep what is needed
Straighten - positioning/accessible
Shine - clean and tidy
Standardise - maintain order, perpetual neatness
Sustain - commitment and pride in keeping to standards

Question 15

Total Productive Maintenance (TPM)

Answer 15

Ensures each and every machine in the production process is always able to perform its required task.
Places the emphasis on production operators being trained to handle routine maintenance on a regular basis.

Question 16

Theory of Constraints (TOC)

Answer 16

Aims to draw attention on the capacity constraints or bottleneck parts of the operation. Increases profit by increasing the throughput of a process or operation.

Question 17

Optimised Production Technology (OPT)

Answer 17

A computed-based technique and tool which helps to schedule production systems to the pace dictated by the most heavily loaded resources - that is bottlenecks.

Question 18

Material Requirements Planning (MRP)

Answer 18

MRP is driven by the master production schedule and seeks to meet projected customer demand by directing that items are only produced as needed to meet that demand. MRP is seen as a ‘push’ system.

Question 19

Six Sigma

Answer 19

Whilst similar to Lean Operations, 6σ aims to eliminate defects and reduce variation. 6σ utilises empirical, statistical methods whereby 99.99966% of opportunities to produce some feature of a part are statistically expected to be free of defects.

Question 20

Single-Minute Exchange of Die (SMED)

Answer 20

Aims to reduce changeover waste, improving flow (Mura). Single minute means single digit, implying all start-ups and changeover should take less than 10 minutes.