Lean construction

1 Introduction
2 UK construction
3 Lean construction
4 Uptake
5 Related articles on Designing Buildings
6 External references

[edit] Introduction

Lean production (sometimes referred to as lean manufacturing) was pioneered by Toyota in Japan after the second world war. The Toyota Production System was considered by some to be the most efficient in the world, and it was claimed that their lean production principles could be applied not only to any other manufacturing process, but also to other business activities.

The term 'lean construction' is an adaptation of lean production techniques applied to the construction industry. Very broadly it can be characterised as techniques aimed at maximising value and minimising waste. Such approaches have been criticised by some for prioritising narrowly construed efficiency over longer term performance.

[edit] UK construction

There is a long-established narrative whereby the construction sector in the UK is seen to perform in a way that is thought to be wasteful compared to other industries. The underlying argument is that it does not deliver good value for its customers. In part this is due to the unusual nature of construction, where, unlike a production line, each building is a one off. But in addition, the nature of contracting arrangements means that it can be adversarial, with significant potential for disputes.

In 1997, the then Deputy Prime Minister John Prescott set up the Construction Task Force, chaired by Sir John Egan. In 1998, the task force published ‘Rethinking Construction' (the Egan Report), on the scope for improving the quality and efficiency of UK construction. Amongst other things, Egan advocated lean thinking, suggesting that it '…presents a powerful and coherent synthesis of the most effective techniques for eliminating waste and delivering significant sustained improvements in efficiency and quality….We recommend that the UK construction industry should also adopt lean thinking as a means of sustaining performance improvement.'

Beyond the touching faith in 'modern' management techniques was an implicit message was that the newly elected New Labour government would place its trust in the market mechanisms of the enterprise culture. There was to be no return to the demand management policies of previous Labour governments, and certainly no return to the policy of building industry nationalisation.

For some, the Egan report is best understood in terms of legitimising the extensive structural change which had taken place over the preceding 20 years. The construction sector had abandoned direct employment in favour of a strategic model of 'structural flexibility'. It hence became dominated by contracting firms who progressively divorced themselves from the physical task of construction. Work was routinely subcontracted through extended supply chains culminating in a workforce that was increasingly self-employed. The institutional fabric of the sector was significantly changed with direct implications for skills, training and social mobility. It can be argued that the uncritical acceptance of this discourse of lean construction is directly implicated in the current skills crisis,

[edit] Lean construction

For its advocates, lean construction is a broad philosophy that has been defined in many different ways and includes a range of different approaches, tools and techniques. For its detractors, it comprises a complex cocktail of instrumental techniques which reflect the industry's default orientation towards simplistic machine metaphors.

It is defined by the Lean Construction Institute as '…the application of lean thinking to the design & construction process creating improved project delivery to meet client needs and improved efficiency for constructors.' Other definitions include, '...a philosophy for working based on continuous delivering of better value to customers whilst increasing business profitability and competitiveness' (ref. Lean Thinking in Construction) and '... managing and improving the construction process to profitably deliver what the customer needs' (ref. Constructing Excellence).

Hence anything which fails to add value to the client is eliminated as waste. It is possible to read such a narrative as a direct challenge to the principles of professionalism whereby architects, surveyors and engineers see themselves as having responsibilities for the quality of the built environment which extend beyond the immediate short-term needs of the paying customer. Recent trends towards the mapping of 'Social Value' can be seen as an antidote to lean construction, but can also be read as 'identity work' on the part of a disgruntled architectural profession.

The advocates of lean construction seemingly have little interest in the systemic implications of forever focusing on short-term efficiency. They also tend to debate forever the very fine supposed differences between lean construction and other techniques. A common argument is that whilst the goals of lean construction and lean production may be similar, the approaches are necessarily different due largely to the project-based nature of construction, i.e. it has a start and end rather than being an ongoing activity such as a production line.

For the believers, lean construction is a continuous process that applies throughout design, procurement, manufacture and construction. It is an 'integrated process' in which clients, designers, contractors, and suppliers must be committed to working together.

Some of the supposed principles underpinning lean construction include:

Improving communication.
Eliminating waste and errors.
Direct intervention to drive immediate and apparent change.
Improving work planning and forward scheduling.
Specifying value from the perspective of the customer.
Identifying the processes that deliver customer value (the value stream).
Eliminating activities that do not add value.
Ensuring the working environment is clean, safe, and efficient.
Continuous improvement.

Many of the above are readily identifiable in the 'scientific management' proposed by Frederick Taylor in the early 20th Century. Other techniques that can be adopted as part of lean construction include:

Using modelling and visualisation techniques to improve planning and communication.
Early planning, to improve workflow, focussing on defining achievable tasks and avoiding mistakes, duplicated effort, out of sequence working and activity that does not add customer value. The objective is the maximisation of workflow and the minimisation of performance variation rather than point speed.
Look-ahead scheduling.
Pre-fabrication and modular building to reduce activity on site and better distribute the workload.
Just-in-time deliveries.
Value management techniques.
Integrating the supply chain through partnering and collaborative practices.
Benchmarking techniques and the use of key performance indicators.
Last Planner System
Critical path analysis and management.
Risk management techniques.
Continuous improvement from one project to another

Several of the above have short-term merit in terms of stimulating critical reflection, but it's interesting how the definition of lean construction is sufficiently broad and flexible to embrace an ever-increasing diversity of differing techniques. Ultimately, it must be accepted as a value-laden web of ideas which are enacted in different ways in different places at different times.

[edit] Uptake

There is some suggestion that the adoption of lean construction has not been entirely successful. To a certain extent this is because many of its techniques are inseparable from other recipes of supposed best practice. Nevertheless, successive reports assessing the industry continue to be highly critical. Notably, the Government Construction Strategy, published in May 2011, suggested '..the UK does not get full value from public sector construction...' and that '…there is broad consensus, spread both across the industry and its customers, that construction under-performs'. Whether or not lean construction is part of the solution, or perhaps forms part of the problem is a moot point.

The Egan report itself was not entirely welcomed, and there were many suggestions that applying lessons from manufacturing to construction was unrealistic (Sir John Egan was chief executive of Jaguar Cars from 1984 to 1990, and chief executive of BAA from 1990 to 1999). In May 2008, ten years after publication of Rethinking Construction, Sir John Egan stated that "...we have to say we’ve got pretty patchy results. And certainly nowhere near the improvement we could have achieved, or that I expected to achieve…..I guess if I were giving marks out of 10 after 10 years I’d probably only give the industry about four out of 10" (ref. Egan: I’d give construction about 4 of 10). Or maybe Egan's ill-defined cocktail of improvement techniques was a distraction from the real issues faced by the construction sector.