ARE YOU lean OR MEAN

What is lean construction?

Lean construction is a philosophy based on the concepts of lean manufacturing. It is about managing and improving the construction process to profitably deliver what the customer needs.

Because it is a philosophy, lean construction can be pursued through a number of different approaches. This fact sheet outlines the elements of lean manufacturing and suggests how these might be adapted to deliver lean construction in practice.

 Lean manufacturing

Lean manufacturing was initially pioneered and developed by the large Japanese car manufacturers. It has been implemented by a number of Japanese, American and European manufacturers with considerable success, and has been widely applied outside the automotive industry.

The Lean Principles

 Eliminate waste

 Precisely specify value from the perspective of the ultimate customer

 Clearly identify the process that delivers what the customer values (the value stream) and eliminate all non value adding steps

 Make the remaining value adding steps flow without interruption by managing the interfaces between different steps

 Let the customer pull – don’t make anything until it is needed, then make it quickly

 Pursue perfection by continuous improvement

Lean is about designing and operating the right process and having the right systems, resources and measures to deliver things right first time. Essential to this is the elimination of waste - activities and processes that absorb resources but create no value. Waste can include mistakes, working out of sequence, redundant activity and movement, delayed or premature inputs, and products or services that don’t meet customer needs.

The primary focus is on moving closer and closer to providing a product that customers really want, by understanding the process, identifying the waste within it, and eliminating it step by step.

Production and management principles

Lean is focused on value, more than on cost, and seeks to remove all non-value adding components and (especially) processes whilst improving those that add value. It aims to define value in customer terms, identifying key points in the development and production process where that value can be added or enhanced. The goal is a seamless integrated process (value stream) wherein products ‘flow’ from one value- adding step to another, all driven by the ‘pull’ of the customer.

 

The idea of ‘right first time’ is essential to the lean philosophy. ‘Right’ in this context means making it so that it can’t go wrong. This approach involves an extremely rigorous, questioning analysis of every detail of product development and production, seeking continuously to establish the ultimate source of problems. Only by eliminating the cause at source can the possibility of that fault recurring be removed.

 

Design and product development

Lean manufacturers have developed systems for product development which first identify the right product (in terms of customer needs), and then design it correctly so that it can be manufactured efficiently.

‘Design’, in manufacturing terms, is concerned with the development and integration of systems and components into coherent, efficient and build able products, not just the styling of the exterior appearance, a task which is often undertaken by external agencies

Tools have been developed to capture and analyze customer perceptions and requirements for product quality and performance. These tools also enable product development and manufacturing performance targets to be established. Design development targets include reductions in design changes and process iterations.

 Critical success factors

 Design is informed by extensive data on the performance of products, systems and components

 Carry-over to new models of a high proportion of systems and components from previous models

 Front-loading of resources towards design to prevent problems during manufacture

 Concurrent working between manufacturer and supplier during design development

Lean Production

Lean manufacturers arrange production in closely located ‘cells’ so that work flows continuously, with each step adding more value to the product. The standard time for all activities is known and the objective is to totally eliminate all stoppages in the entire production process. However, only optimum stocks of material are kept as buffers between processing stages.

For this system to be effective, every machine and worker must be completely capable of producing repeatable perfect quality output at the exact time required. Workers are responsible for checking quality as the product is assembled, and in some instances given authority to stop production if defects arise. In this way, quality problems are exposed and rectified as soon as they occur.

The workforce is kept informed of progress towards their production and cost targets by use of information displays so that everyone is able to see the status of all operations at all times. Work teams in lean manufacturing are highly trained and multi-skilled, and many of the traditional supervisory and managerial functions have been devolved to them.

 Critical success factors

 In depth understanding of production processes and resources involved in them

 Responsibility and authority placed with the workforce

 Real time feedback on performance

 Training and multi skills

Supply chain management & supplier relationships

Lean manufacturing is based on the elimination of waste, including time lost waiting for missed/delayed supplies, unnecessary storage and the value tied-up in large stocks of parts waiting for assembly. ‘Just in time’ (JIT) delivery is therefore a vital element, and to deliver this lean manufacturers have had to develop their network of suppliers. Significant efforts are applied to encourage them to adopt the same lean manufacturing principles and systems, often company-wide, rather than solely related to that part of the suppliers’ operations that affect the manufacturer.

Lean manufacturers have moved away from traditional relationships with their suppliers to partnering arrangements with a smaller number based on good communications and open-book accounting. These relationships work by both parties sharing philosophies of continuous improvement (especially in the area of defect reduction, cost and timeliness of delivery) and sharing business and development strategies sufficient for both parties to know enough about each other to make forward planning effective.

Critical success factors

 The lack of reliance on formal contracts

The use of bench-marking of suppliers’ performance against each other on a range of generic criteria

 The development of close relations with first tier suppliers

Applying lean thinking to construction

The lean principles can only be applied fully and effectively in construction by focusing on improving the whole process. This means all parties have to be committed, involved, and work to overcome obstacles that may arise from traditional contractual arrangements.

 

Design

 Use of visualisation techniques such as Virtual Reality / 3D CAD / BIM to fully define the product requirements from the customer’s perspective.

 Value Management to achieve more understanding and focus on client value.

 Use of integrated design and build arrangements (including partnering) to encourage close co- operation between designers, constructors and specialist suppliers.

 Design for Standardisation and Pre-assembly - both of components and processes to achieve higher quality and cost and time savings

Procurement

 Supply chain management and rationalisation of the supply chain to integrate all parties who contribute to the overall customer value into a seamless integrated process. Transparency of costs - the elimination of waste in both processes and activities requires a clear and complete understanding of costs to ensure decisions on customer value can be taken. Confidentiality of cost and cash flows must be addressed.

 The concept of partnering, all involved parties contributing to a common goal with the boundaries between companies becoming less critical.

 Production Planning

 Benchmarking to establish ‘best in class’ production methods and outputs

 Establishment of a stable project programme, with clear identification of critical path.

 Risk management - to manage risks throughout the project

 

Logistics

 Just-in-time delivery of materials to the point of use eliminates the need for on-site storage and double- handling

 

Construction

 Clear communication of project plans

 Training, teamwork, multi-skilling

 Daily progress reporting and improvement meetings

 A well motivated, well trained, flexible and fully engaged workforce.