Resource efficiency through Lean waste management
14 January 2015
The purpose of this article is to investigate the opportunities for improving resource efficiency in construction projects through the implementation of Lean construction philosophy to the construction process. The case studies will hopefully outline the processes and identify the actions that can be easily applied to other projects to achieve similar improvements.
What is Lean construction?
Lean thinking is a philosophy that seeks to maximise value through the elimination of waste in the activities required to construct. Lean principles have their origins in the Japanese manufacturing industry, whereby a management philosophy was created in the 1980s to drive out inefficiency by analysing the production process, identifying the activities and addressing those that are either inefficient or add little/no value. This approach has allowed costs to be driven down without detriment to time or quality. Essentially, value considers the impacts on quality, price and programme. Clearly, the removal of inefficient activity in the construction process does not just have environmental benefits in terms of the reduction in CO2, raw material usage and waste arisings, but also has a tangible commercial benefit to clients and contractors delivering construction projects. Applying these benefits further, implementers can expect shorter programmes, reduced costs and higher quality works. Lean thinking sits closely with the continuous improvement process of ‘plan-do-review’ to: identify areas for improvement, investigate the options and prioritise implementation of the easiest and most beneficial.
- To start the process, your organisation should assemble the relevant parties at a workshop to breakdown the process into its activities, identifying the problems and known inefficiencies. Use flow charts to map out the activities and undertake site visits to get first-hand experience of the issues. The output will be a detailed list of issues that the team can then prioritise, and take ownership of to investigate feasibility.
- Once the waste reducing actions are agreed, your team needs to set a baseline (how long an activity took before, or cost) so you can measure how much you have improved.
- Once agreed, you need to make all staff aware of what you are changing and why so. Prepare briefings, newsletters and posters to ensure all staff are informed.
- During implementation, you may want to pause to check that the process is working.
- Review – after a reasonable period of time has passed, review how well your actions have improved work flow. Review against programme to complete.
- Continue to investigate further areas for improvement.
Currently, Farrans Construction is involved in the second-largest business improvement project in the UK construction industry. We have initiated a two-year growth-fund programme focusing on the “alignment of the end-to-end Scottish Water infrastructure supply chain to improve productivity, quality and reduce wastage, encourage sector growth and improve the value of outcomes for all stakeholders”. The Scottish Water Infrastructure Growth & Skills (SWIGS) programme has secured funding from Construction Industry Training Board/Construction Skills. The programme will support a sustainable solution for organisational growth long after the growth funding programme is complete. Farrans is working collaboratively on the SWIGS programme with three other infrastructure contractors: Barhale, George Leslie and Morrison. It is vitally important for us to work together, share best practice and improve performance. SWIGS has initiated projects to improve squad productivity, introduce standardised products and realise the benefits of pre-cast manufacture. We have also involved the National Construction College to develop a training package to enhance operative and management skills in the critical areas of reinstatement, service avoidance and traffic management. It is planned that this innovative approach to training to support growth will be disseminated throughout the Group, and we will seek to collaborate with our trade body, the Civil Engineering Contractors Association, to achieve this aim in conjunction with 6ix Consulting. One such improvement project focused on the application of workplace organisation through 5C at Farrans storage yard near Edinburgh and its effect on material re-use. The yard operates as the central distribution hub for around £40 million of works per annum with material values equating to around £10 million per annum.
Applying the Lean process
Through the Lean intervention, a series of scoping workshops were held to identify the main activities and areas where material savings could be made through the application of Lean thinking. The team were encouraged to talk openly and constructively about how contracts were delivered and where improvements could be made. There was a perceived area for improvement relating to the ordering, programming, control and storage of materials associated with water infrastructure works. The yard was identified as being typical of storage and material handling facilities across Scotland. Issues identified
- Changes in design can have significant impacts on materials used. Often these design changes occur late into a project once materials have already been procured.
- The opportunity to re-engineer projects to reduce material usage is limited due to time of involvement of the contractor.
- Client processes often cause over-ordering of materials, e.g. different-sized couplers to ensure loss of supply to customers is limited.
- Materials storage and control is critical if materials are to be re-used on other projects.
- Materials currently moving through the yard are not being well controlled, making it difficult to re-use materials.
The majority of the improvements were anticipated to come from changes to material handling, storage and controls within the yard itself. It is also worth noting that the majority of the materials held in the yard were those already bought for previous projects and not used. The re-use of any materials is therefore effectively free-issue and has a direct impact onto bottom line profit levels. Main contractor profit levels are typically running at between 1% and 3% at present and therefore the re-use of relatively modest values of materials equates to significant project values when factored. As an example, re-using £50,000 of materials equates to winning and delivering a £3.3 million contract at a margin of 1.5%.
Workplace organisation through 5C
The tool 5C, also known as 5S, is one of the foundations of Lean improvement. It is often seen as simple housekeeping or tidying-up but is actually a technique designed to eliminate the wastes of transport, inventory, defects and many more. It can be defined as a structured method for achieving, maintaining and improving the standard set-up, organisation, layout and control of a work area, so as to ensure safe and efficient operations with minimum waste. The concept of 5C is generally considered as one of the fundamental building blocks for an organisation striving to establish Lean practices and a culture of continuous improvement. The original 5S has been translated from the Japanese version into a number of different Western forms, as shown in the table below:
- Clear out
The first stage is to sort out the essential and used items from the rubbish or rarely used ones. In order to sort the workplace, it is usual to identify areas that the removed items will go into, a keep area, a quarantine area and a rubbish/recycle area. As part of the clear-out phase, the catalogue of materials was updated and made available to all project managers working from the yard. The resulting spreadsheet was used as the first source for procuring materials. In this manner the materials are first drawn down from the already purchased list before identifying shortfalls that are then procured in the traditional manner from suppliers.
This step can be best described as ‘a place for everything and everything in its place’. In other words, ‘the orderly organisation of those items necessary to complete the work activity, in a way that ensures safe and efficient operations and can be repeated with minimal waste’. The site containers to the rear of the yard have been configured to control the majority of the smaller pipes and fittings. The containers were racked out to ensure that the materials are easily accessible and stored most ergonomically. Labelling and visual management techniques are gradually being introduced to help maintain the standard of the configuration and ensure that materials can be found and identified easily.
- Clean and check
The third step is the first of the management activities and is designed to keep everything in good order. The clean and check regime will include an audit and physical tidy to maintain the workplace in the same standard as it was after the previous steps. A clean and check audit sheet has been introduced to the yard which outlines the standards to be achieved and scores against this.
The fourth step is predominantly a management activity to maintain the standards set in the previous three steps. A standard work approach may be used to ensure that these steps are maintained or alternatively forms, diagrams, check lists and roles and responsibilities can be adopted. This step should introduce a process by which the 5C standards can be maintained and would typically include:
- Pre-work set-up checklists
- Displays of how work tasks should be done
- Displays of the 5C standard of the work place
- Define how the 5C standard is to be maintained (e.g. Clean & Check Rota)
- Visual methods to show the location of necessary items
A number of procedural changes have been introduced to ensure that the benefits gained from the first three stages of the 5C exercise will be maintained. One of the most significant of these has been in the manner in which we contract with our sub-contractors.
- Custom and practice
The final step deals with ensuring consistent adoption and use of 5C by all personnel who are either involved directly with the work place or who interact with the workplace. Its aim is to make people want to keep applying good practice in workplace organisation and housekeeping and then apply continuous improvement to it. The successful adoption of a 5C regime can be seen as a mixture of physical actions, management activities and a change in culture of the workforce. This project has identified the opportunities that are provided by a methodical approach to a problem all too common across the construction sector. Whilst the yard exercise has identified around £150,000 worth of materials that are planned for re-use by the end of 2014 this is only a fraction of the savings that could be achieved by changing the cultural mind-set towards workplace organisation and 5C. One final observation is the obvious link between 5C and improvements in health and safety which may support the implementation on a wider scale.
The Continuous Improvement Model and collaborative planning
Currently, Farrans Construction is nearing completion of the Harestanes Windfarm infrastructure project. This project involves infrastructure for: – 68 turbines; – 63km roads; – 275,000m of cable; – Substation and control building; – Seven quarries to extract approximately 600,000m3 of rock; and – Concrete 32,500m3. The project was programmed to be completed in less than one year. Recently, the Harestanes site team commenced a course on business improvement techniques. The course was run by 6ix Consulting to introduce a more collaborative approach to planning the works and specifically look at the two week look-ahead programme. From the first session, it was estimated that on average only 50% of planned activities were completed within the timeframe set out in the two-week ‘lookahead’. This could be due to a number of reasons e.g. weather, design issues, lack of resources, unplanned work, etc. To review the effectiveness of the programme a ‘Planned Activities Complete’ (PAC) analysis was implemented:
- Each task was broken down into activities of no more than four days. This made it easier to monitor progress.
- At the end of every week, the section engineer records the tasks complete/non-complete and reasons for delay. The PAC percentage is then calculated.
- Reasons for delay are summarised to show the number of re-occurrences /trends that are evident.
One of the main causes for delay resulted from poor planning of the shared resources (sub-contractors) for each of the sections/work areas.
Throughout the construction phase, some 68 turbines across the sections required 11 visits from the sub-contractors. The average travel time between sections is 30 minutes. Each section engineer would notify the sub-contractors individually when a visit was needed. Problems arose as section engineers were not aware of the conflicting needs of other sections and reliance was put on the sub-contractors to plan and prioritise tasks to meet our schedule. Inevitably tasks were not being completed at the times required. This resulted in delays and standing time charges from the follow-on trades. The overall cost of sub-contractor delays were estimated at over £300,000. To minimise this, a ‘Visual Management’ (VM) board was implemented and displayed in the site office as shown below.
This was marked-up by the section engineers every evening and tasks prioritised across each section. A photograph was taken at the beginning of every shift to ensure no changes were made during the day. This encouraged forward planning and introduced a more collaborative approach to management of the shared resources throughout the site. Each sub-contractor would refer to the VM board at the start of each shift, making it easier for them to plan their daily activities. As the site has minimal phone reception, the VM board provided the best way of communicating the tasks to the sub-contractors reducing the volume of radio traffic. As tasks were completed, they would be ticked off and section engineers could monitor progress and follow up on any incomplete tasks. The benefits of the VM board could be seen almost immediately and was welcomed by the sub-contractors. The PAC percentage increased significantly and standing-time charges reduced, leading to estimated savings of circa £250,000. Farrans Construction is a building and civil engineering contractor operating throughout the UK, Ireland and a number of European locations. Farrans is an operating division within Northstone (NI) Ltd, whose activities include aggregate production, manufacture and supply of quality building materials and utility access chambers. Northstone is a wholly owned subsidiary of CRH plc. Headquartered in Ireland and with a turnover in excess of €18 billion, CRH operates in 35 countries, employs approximately 76,000 people and is focused on three closely related core businesses: Primary Materials, Value-Added Building Products and Specialist Building Materials Distribution. Farrans is an award-winning contractor with a core of expertise that has kept us at the forefront of innovation and modern construction techniques for over 70 years.https://www.engineersjournal.ie/2015/01/14/lean-construction-waste-management/https://www.engineersjournal.ie/wp-content/uploads/2015/01/Construction-1024x683.jpghttps://www.engineersjournal.ie/wp-content/uploads/2015/01/Construction-300x300.jpgCivilconstruction,Farrans Construction,lean