The many tools of Lean

There are a multitude of ‘tools’ that are associated with Lean. Whilst many commentators caution that Lean should not be seen as a set of tools (Bhasin, 2008; Emmiliani, 2008; Schönberger, 2007; Holweg, 2007; Womack and Jones, 2006; Liker, 2006; Roth 2006; Spear 2004), tools do have a place in helping us to identify waste and assess whether and how it can be eliminated when they are used correctly and built on strong foundations that consist of leadership, alignment with strategy, learning and training, and engagement of staff (Bicheno, 2004; Hines et al, 2008; Radnor 2010b). In linking Lean tools to the five principles of Lean proposed by Womack and Jones (2006), Bicheno (2004) differentiates between tools that identify ‘value’, tools that prepare for ‘flow’, tools for mapping and analysis, tools for ensuring quality (reducing defects) and tools continuous improvement. Table 2.2 lists some of the most commonly cited tools with a brief description of their use.

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Table 2.2: Some common tools associated with Lean

Tools for identifying value

Kano model A method for identifying ‘basic’ factors (what the

customer expects to be there – eg. clean sheets in a hotel), ‘performance’ factors (features such as speed of service delivery or ease of use), and ‘delighter’ factors, these are what the customer does not expect but their presence causes delight e.g. a bottle of wine awaiting guests in a hotel room (Bicheno, 2004).

Pareto analysis Pareto analysis uses the Pareto principle which is

the idea that 80% of problems are caused by 20% of sources. Pareto analysis is a tool that helps organizations identify and prioritize problem solving.

Tools that prepare for ‘flow’

Takt time Where the pace of production is set to the pace of

demand. For example, if your customer demand is for 7 vehicles per day and you have 7 hours available time then the Takt time is 1 vehicle per hour.

5S A structured approach to standardisation, akin to

‘housekeeping’ it has the objective of keeping everything in order to reduce time wasted looking for things and to improve visibility at a glance. 5S consists of: sort, straighten, sweep, standardise and sustain.

Standard Work All work should be standardized and unambiguous.

It is this standardization of work that provides a platform for continuous improvement (Spear and Bowen, 1999)

Total Productive Maintenance (TPM)

TPM goes beyond breakdown maintenance and focuses on prevention of breakdown through predictive and planned maintenance of machinery and equipment to extend the lifetime of equipment and reduce downtime due to machine breakdown and failure.

Changeover reduction Originates from Shingo’s SMED (Single Minute

Exchange of Die), the concept refers to the reduction of set up time to the absolute minimum. To quote a popular saying of Shigeo Shingo: “it is only the last turn of the bolt that tightens it – the rest is just movement”.

Small machines The use of small machines usually means the capital

outlay is smaller and they are easier to move so that the process layout can be arranged to reduce waste in the form of excess transport.

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allow for ‘flow’ (Bicheno, 2004).

Tools for Mapping and Analysis

Value Stream Mapping A value stream is all the actions (both value-added

and non-value added) currently required to bring a product to fruition. Helps people look at the bigger picture of material and information flow rather than discrete operations and processes, i.e. it is about

‘learning to see’ (Rother and Shook, 2003)

Process Mapping Focuses on actions at the level of the process.

Spaghetti diagrams A graphical aid often used to illustrate visually the flow of a product/service, or the walking patterns of workers in a process for example. The resultant graphic often resembles a mass of cooked spaghetti.

Tools for ensuring quality

Pokayoke Error-proofing processes so it is near impossible to

make a mistake, for example a petrol nozzle that does not fit into a diesel car.

Visual Management The concept of visual management is to enable

anyone in the workplace (even those unfamiliar with the work) to understand the current status of the operation at a glance.

Tools for Improvement

PDCA Also known as the Deming cycle, PDCA is an

acronym for the continuous improvement cycle of ‘plan, do, check, act’ where ‘plan’ refers to understanding the problem, ‘do’ refers to implementation of a pilot/proposed solution, ‘check’ means to check (measure) the effectiveness of the piloted solution and ‘act’ means to implement the solution fully.

Kaizen events/rapid

improvement events (RIEs)

Kaizen refers to ‘change for the better’ based on small incremental improvements over time (Imai, 1983, 1997). A kaizen event or RIE as they are frequently known refers to a short burst of improvement activity usually taking place over 3-5 days with a cross section of worker involved in a particular process.

Root causes A process for dissolving problems by establishing

the ‘root cause’. 5 why analysis is a common tool to establish ‘root cause’ as is the ‘Ishikawa’ diagram/‘fishbone’ diagram.