Towards Zero Defects (TZD) Toolkit

April 2008

Contents

  1. Introduction
  2. Context
  3. What the CIRIA team did
  4. What are ‘defects’?
  5. Toolbox of signposting for the industry
  6. Toolkit of messages for participants in the building process
  7. Conclusions

Appendices

  1. The study team
  2. Core reasons for defects
  3. Categories of defects
  4. Activity in participant organisations

Feedback



1. Introduction

This toolbox is the output from a CIRIA collaborative study project during 2006/7 in which a team of people (see Appendix A) with first-hand knowledge of the issues involved worked as a team to deepen their personal understanding and to agree as a team what would enable improved performance on projects.

As part of this work the CIRIA team investigated defects on current projects undertaken by their organisations and discussed their findings as a team. They also contributed their personal and corporate experience. The resulting knowledge has been assembled into this toolkit, which is offered to the construction industry for use and reference. Information is also provided showing how the organisations of the participants are seeking to improve.


2. Context

A. The problem. The main problem is that clients experience unfinished construction at handover. Late identification and rectification of defects left at handover acts as a dampener on many otherwise successful projects; defects are not the only indicator of success but they can spoil an otherwise successful project. Things are not finished properly or they do not work as hoped. Sometimes the problems are resolved to some degree but recur and cause more problems. These types of experiences apply from the most humble jobs up to prestige developments. They lead to disappointment, arguments, disruption, waste of money, energy, time and loss of reputation – and sometimes to litigation.

There is a secondary problem; the waste, cost and disruption which arise from defects during the construction process. This has traditionally been accepted as 'normal' – problems are experienced and overcome. In fact, studies have shown that cost alone is a significant issue, and the delays and disruption flowing from defects during construction can impact upon successful completion and handover.

One thing in particular was common amongst the team; we agreed that an efficient modern industry can achieve high levels of customer satisfaction only when defects have been driven out of the process, so that they are an aberration and not an accepted part of the delivery system. The benefits of reducing defects to a zero level would be to lift our performance to a higher plane should benefit all parties.

The aim of the project was to discuss how we can improve this situation.

B. Earlier UK work. An earlier study (reported in 1998) sponsored by DETR and involving 20 participants at a series of workshops, had reported that critical factors to be addressed were:

  • a client’s needs and formal definition of the project performance requirements need to be clearly defined and communicated to the whole project team
  • project team to be established as early as possible and maintain its stability
  • deliver through a clearly-defined, measured and managed process.

C. Changing industry environment since the DETR report. Both the Latham and Egan initiatives sought to improve the performance of the construction industry; whilst there was passing reference to the defects issue, there was no focused advice; there was however an expressed awareness that the industry needed to perform better and particularly (Latham) as a team and (Egan) in a more structured manner. The messages from these reports are echoed in this toolkit.

D. International perspective. This project was not able to examine international construction practice – and we were aware of little of relevance relating to the construction industry which was being done elsewhere. However, there was one reference to the issue of quality in Japan: the Reading Construction Forum report 'Seven pillars of partnering' states that: 'Japan is the most efficient construction industry in the world. 'Zero defects' is a reality for many major customers'.

The toolbox was launched at an event held by the CPN (CIRIA's process and technology network) in London on 7 April 2008. At the launch, three of the group spoke about their personal experiences and there was also open discussion with the delegates to the event. A workshop report from the launch is available in CIRIA Resources

3. What the CIRIA team did

The CIRIA team worked through a series of four workshops, building on the earlier work.

At the first workshop we looked at the current situation and discussed the earlier work. We noted that actions from the DETR study referred to above which were awarded a high level of priority were as follows:

  • use a checklist to develop the project brief and cascade to all
  • partner with trade specialists ASAP
  • appoint a project interface manager
  • formalise project review and maintain a database of learnings
  • have a change management process for changes in client requirements.

The conclusions of the DETR study were focused upon the ‘big picture’. The CIRIA team initially focused upon the defects themselves. Numbers and categories of defects were identified and the reasons for them explored. Further information on the work carried out by the team at this first workshop is provided in Appendix D.

At subsequent workshops we considered what we had learnt within our own organisations; information about some of the initiatives underway is provided through Appendix D. The team explored the reasons for lack of defects on projects which they had been involved in and identified the success factors and they analysed live projects to understand better how defects arose and their management and consequences. We also had a session devoted to the important issues related to the work of specialist contractors and in particular M+E. From all this work we agreed messages for industry (see Section 5) and for participants in construction projects (see Section 6).

We also looked at the underlying ‘core’ issues which must be at the heart of all defects, as presented in Appendix D. This work could be developed and taken further by future studies.

None of our suggested issues and what to do about them are presented as tablets of stone to be digested by others. Rather, we found the subject complex and our approaches to it quite diverse, so that the thoughts presented are meant to be used to promote thought and activity to suit the many diverse situations within which we in our industry operate.


4. What are defects?

The construction industry uses various relevant terms. The prime concern is the situation at handover to the client, 'Practical Completion' (PC). During the period of activity on site leading up to handover, 'Snagging Lists' (also known as 'punch lists') are prepared to deal with all outstanding issues – but they are usually focused upon defective and incomplete work. It appears to be accepted that there will be some defects to resolve after PC because there is then a 'Defects Period' during which defects are dealt with, leading to 'Final Completion' (FC), normally after a year.

The definition of what is 'defective' can be contentious because of different expectations and perspectives. For example, where finishes are concerned – the preparation of samples of work (panels etc) which are agreed (at an early stage) to be acceptable has been found to be a good solution. Where specific tests have to be passed (e.g. roughness for a floor surface) the sample floor area would need to be tested and shown to have the required characteristics.

The treatment in contract of the remedying of defects after PC is normally loose. Resolving the issues of timing, access, secondary damage etc is often tedious and costly in terms of both money and relationships. These costs are however visible; costs during the construction process are generally hidden.

The industry manages the effects of a wide range of problems throughout the construction process and (after handover) throughout the life of a structure. Most of the defects during construction are dealt with as transitory problems – but they may well disrupt the work (particularly the programme) and plant the seeds of future problems due to ‘bodge-ups’ and problems which are only partially or superficially resolved, so that they recur later. The costs have to be absorbed within profit margins or feed through into higher out-turn prices, leading to less overall value-for-money for clients.

This study therefore examined defects as a continuum. The range of things which could go wrong was agreed to be far too extensive for detailed listing, but there was some issues and factors affecting them which were seen as being common and worth capturing – these are set out in Appendices B and C.

As far as a client is concerned, a defect could be defined as: 'An occurrence or malfunction which affects the performance or amenity of part of the built structure either directly or indirectly at some time during its design life when judged against the project brief, specification and cost plan'.

For the purposes of defects at handover a simpler definition is preferred: 'any item of work, workmanship, plant or design which is either incomplete when offered for inspection, not in compliance with the drawings and/or specification, benchmarks or samples, damaged or of indeterminate quality (including the absence of certification or records)'. In this respect, handover may be to the client or to a managing contractor.

For the consideration of waste and delay/disruption during construction, i.e. defects in the build process, a definition could be:'any item of work, workmanship, plant or design which causes additional (unplanned) work to be carried'.

In striving for Zero Defects, whilst the prime aim is 'No defects at handover', ideally there would be no defects at any time. In business management terms, trying to reduce waste and its costs, this latter (wider) aim is worth consideration and fits with the 'lean thinking' concept. Hence, in a whole-life sense, a definition could be: 'an adverse occurrence or malfunction which affects the project during construction, at handover or during its life'. This might include for example piles being out-of-position causing a re-design of the foundations or the thermal performance of a building not meeting expectations and increasing fuel lifetime consumption.


5. Toolkit of signposting for the industry

The project participants identified a wide range of issues which affect defects and agreed (from their experiences) the approach which would drive them down. The key issues were as follows:

  • setting and meeting expectations
  • the procurement process
  • working in teams
  • design
  • site responsibilities
  • site quality systems
  • programme
  • risk management
  • technology
  • management of change
  • retro-fitting and correction
  • PR and client-handling
  • feedback
Toolkit sections:

Setting and meeting expectations. We agreed with the DTI study that understanding the quality levels required by clients is important. The requirements may not be well expressed in standard specifications, such that what is acceptable to one client may not be acceptable to another. An example would be acceptance (or not) of some cracking in plasterwork (cracking of plaster over a brittle base being almost inevitable).

The understanding must be communicated to those doing the work. Ideally, an understanding of what is required will be laid down in a manner which can be referred to by all parties and can be trickled down from client to designers, main contractors and specialist trade contractors. There therefore needs to be a consensus of understanding on quality issues between all parties. For complex projects, the project requires a statement of requirements with evidence against which performance can be judged by the client and/or their representatives.

Specific quality standards should be set through documentation and/or (in practice more effectively) through samples, mock-ups and trial work. What will be required at handover needs to be clearly understood from an early stage of a project, including documentation required for acceptance.

The procurement process. We all agreed that the contractual environment in which people operate is crucial. Excessive price competition and failure to value and foster long-term relationships are recipes for disaster because the industry is well versed in cutting corners once a loss is projected. In other words, 'you get what you pay for'.

Working in teams. It was agreed that a co-located design and construction team will be better placed to deliver; lines of communication are shorter, urgent issues can be dealt with fast and pride in the product should be shared.

Design. Design was agreed to be important in terms of the risk of having difficult issues which took time and money to resolve. Design management and coordination is crucial, especially management of interfaces, continuing through to the incorporation of specialist contractor design. Acceptance of delayed inputs to design work is fed by a lack of definition of what is required and when, and this lead to a situation where work has to be carried out in a hurried manner, at the last minute.

The accepted design culture is one of accepting late information, leading to bunching of work, 'muddling through' and the inevitable lack of QA and 'slip-ups'.

In addition, input from future operators/users and from those who will be responsible for future maintenance , as well as from specialists, could avoid problems later; this is referred to as 'design for operation'.

Site responsibilities.
Success in establishing a site team which cares about quality is crucial; this requires the right mix of skills and some training may be required. One person should be responsible overall for management of the site processes for quality/defects, getting others involved and monitoring and reporting on their performance.

Specialist subcontractors should be appointed early so that there is time for them to be inducted into site processes and project expectations before the physical work starts.
Avoidance measures against damage to completed work can be taken through proper arrangements for safe access, protection of completed work, safe storage of material and good traffic management – all of which will contribute to a better outcome.

Site quality systems.
Paperwork per se is not the answer – what matters is having an approach which makes sense, is understood and respected – and which works. Key aspects were:

  1. All parties must understand the site QA process before their contacts are signed
  2. Risk issues should be identified and addressed by the team; this should be followed through in briefing specialist package contractors and then operatives. A library of images of good/bad may help.
  3. The close-out process must be planned through to inspection and testing plans
  4. Close things out as you go – a big rush before handover is hopeless
  5. Tie payment to handover of work packages (e.g. by room) including any rectification being completed
  6. Do not allow specialist subcontractors to leave site until all rectification is completed and any documentation being supplied; final payment to be conditional on this
  7. For defect-free completion:
    • log the defects as the work is done
    • expedite remedial work as-you-go
    • assign tasks and agree timescales
    • physically check remedial work has been done
    • manage the process
    • one person responsible for managing the process
    • weekly reviews at top site management level
    • a through-project programme of inspection with the client and his representatives to check quality levels achieved are acceptable
    • no reliance upon last-minute inspections/lists from the client’s representative.
  8. Feedback lessons learned.

Programme. The need to perform to a 'tight' programme is potentially critical for defects because most teams are inexperienced in fast delivery and will 'carry on as normal'.

Programmes should be developed in consultation with specialist subcontractors (e.g. at a collaborative team planning workshop); they should include for commissioning, a defects sweep-up period and available float – all of which should ensure completion on time and with defects rectified before handover, provided that the float is 'defended' and not used indiscriminately.

One underlying issue which was raised by the specialist building services contractor we consulted was the difficulty of planning anything (but particularly the allocation of people) when the supply of project work is indeterminate, with start-times even for known work being subject to last-minute change.

Risk management. Many site problems can be identified and dealt with before they cause difficulties, if there is a project risk log owned by all the parties. Defect management, identification and correction risks should be included in the log.

Technology. Adopting new materials and product technology in the build contains inherent risks. Tried-and-tested solutions are (obviously) lower risk and less likely to lead to defects. This has to be recognised and managed; cutting-edge designs may warrant a new approach in which defects are actively sought by beta-testing at an early stage in the build.

Similarly, systems such as mechanical services are increasingly complex and this must be recognised and managed; the skill of systems integration was recognised as essential for such systems i.e. how M+E fits into a building’s architecture.

Managing change. Untimely change is the enemy of good order and quality on site. Late changes should normally be resisted and if imposed should be allowed for in terms of management time, programme impact (often unforeseeable) and cost impact (likewise).

Retro-fitting and correction.
The traditional method of post-handover working was agreed to be expensive and uncertain, for many reasons.

PR and client handling. Defect-handling post-handover can have a huge impact on clients and affect their likelihood of re-employing companies. For doing rectification work, a special team may be the best approach for contractors. Demonstrating to a client that his problems will be dealt with fast is an effective way to regain confidence.

Feedback. It was agreed that feedback processes are often poor; the industry constantly reinvents the wheel. This cycle of re-learning may be broken if we move to sustainable procurement with stable teams and if there is more use of pre-fabrication involving a more stable workforce situation. Lessons should be learnt not only by the team involved but also by others in the organisation, including those bidding for and planning future projects.


6. Toolkit of messages for participants in the building process

The messages shown have been agreed by the CIRIA team. Some people or organisations may play more than one role on a project and all will be part of ‘the project team’.


Toolkit sections

Informed (repeat) clients and client representatives

  • Use the Project Scope statement and supporting technical documentation to define the performance requirements and the quality of construction required, for both designers and ultimately people on site to understand what you require.

  • When selecting members of the team (companies and key people) ask how they minimise and resolve defects; are they aware of the CIRIA toolkit?

  • Achieving (when possible) a project team which is co-located at or near to the site will greatly improve chances of success.

  • Involve future users and facility managers.

  • Drive the use of a 3-d project model to reduce clashes and to check out construction and maintenance issues; it is necessary for the team to know who is charged with (and being paid for) this task.

  • Do not press for VE/cost-cutting exercises once the project is rolling, without recognising and accepting the risk of mistakes and unpredictable knock-on effects; get them done at scheme design stage and then stick to your decisions.

  • Make sure documentation is being acquired as the work is being done (as getting it afterwards is never easy) by asking to see drafts well before handover.

  • Ensure feedback from previous projects is shared with the new project team

  • Get involved with the handover process by attending pre-handover inspections.

  • Ensure that the main contractor has clear ownership of the defect rectification and records process and has appropriate personnel engaged on this work.

Casual (one-off) clients
  • Find an adviser with a record of success; follow up references by calling up key people.
  • Do not start construction until a design which meets your needs is fully documented; make sure what is important to you is clearly shown.
  • Avoid making any changes after construction starts; if you must, seek agreement on changes to cost and programme before instructing (but you will be in a weak position).
  • Do not accept handover if there are defects; if you must, have an agreement in place for remedial activity (timing, access, who pays for disruption etc).
  • For further advice, you may like to look at the tool for informed (repeat) clients and client representatives.

Constructors – business team

  • Select specialist package contractors who have performed before, with named key personnel you know.
  • Select as package contractors sound stable companies you know above cheaper options who may skimp or go out of business.
  • Consider the use of off-site prefabrication.
  • Promote with clients the use of 3-d project modelling to reduce clashes and to check out construction and maintenance issues.
  • Ensure the Site Team have a way of voicing their opinions and concerns early in the project execution process.
  • Avoid splitting work into too many packages; you lose control, have too many interfaces and specialist contractors with small value packages cannot afford site management presence (a fatal cocktail).
  • Document the process for snagging and handover/acceptance in subcontracts
  • Resist late-in-the-day VE/cost-cutting exercises as they lead to mistakes and have unforeseen knock-on effects.
  • Plan for post-handover defects work as a customer care activity; use a separate specialist team?
  • Arrange or participate in ‘lessons learned workshops with the client, the site team and your supply chain; incorporate lessons learned into your companies work.
  • Cost implications for the business of defects – both direct and indirect – suggest that ‘defects’ is an area for study/learning/process improvement and can deliver satisfied customers and cost savings. Each company needs to work on these issues and improve its processes and performance to deliver greater client satisfaction and enhanced margins.

Constructors – site team

  • Snag and close-out work as it is done, with joint sign off followed by payment.
  • Motivate and provide leadership to site operatives.
  • Foster team working and reward operatives for good performance (e.g. no reportable accidents, no ‘accidents’/vandalism in a month = raffle for a weekend break).
  • Appoint an experienced coordinator for sensitive interfaces (especially cladding).
  • Set out to identify and then manage areas of particular risk, working with specialist package contractors.
  • Support the use of a 3-d project model to reduce clashes and to check out construction and maintenance issues.
  • Promote the use of images, samples, mock-ups, trial work as benchmarks for quality; get client and designer buy-in.
  • Set out to manage and minimise damage by ‘others’, particularly where the works are in parallel with continued operation of the client’s undertaking.
  • Make sure documentation is acquired as the work is being done; getting it afterwards is never easy.

Specialist package contractors

  • Request early involvement to assist and influence design decisions / specification and input constructability advice.
  • Consider the use of off-site prefabrication in your proposals
  • Do not leave the job unfinished – it never pays.
  • Work with the constructor and other specialist package contractors to identify and then manage areas of particular risk; brief and involve operatives in the response.
  • Make your foreman responsible for quality; prepare and use snagging lists; get sign-off from the managing contractor.
  • Include quality and ZD in toolbox talks; use good ideas from operatives; reward them.
  • Check operatives have full instructions, understand them and can do the work properly.
  • Support the use of a 3-d project model to reduce clashes and to check out construction and maintenance issues.
  • Make sure documentation is prepared and provided as the work is being done; getting it done afterwards is never easy.

Design managers and coordinators

  • Recognise the complexity of design as a process and explain it to others.
  • Ensure adequate resources for this work, once its importance is recognised and understood.
  • Plan design work, defining inputs and outputs associated with each design activity
  • Record design decisions and stick to them.
  • If change occurs, manage it carefully and don’t skip on QA – this is when you need it.
  • Get designers together for workshop sessions, involving specialist contractors and key suppliers.
  • Get early-stage input from specialist designers – don’t wait as key decisions will get made.
  • Agree details and interfaces which reduce risk (e.g. tolerance issues, access, coordination, materials etc).
  • Support the use of a 3-d project model to reduce clashes and to check out construction and maintenance issues.
  • Make sure documentation is acquired from designers as the work is being done; getting it afterwards is never easy.

Site operatives

  • Work for companies who want to do a good job – they last longer.
  • Cooperate in site initiatives to reduce the problem of defects.
  • Do a good job and clean up behind you – you will be used again.
  • Don’t mess up work by others – you may make enemies and incur significant cost to the client and preclude yourself from future work.

Designers

  • Resolve all possible issues before work starts on site, consulting those who will do the work if at all possible.
  • Monitor closely and actively resolve outstanding design issues and design-driven defects, before others make you.
  • Keep the design buildable, maintainable and affordable.
  • Ensure design is coordinated and pre-requirements are clearly defined within the projects specification [mock ups, testing, samples etc].
  • Work with specialist suppliers and designers for early technical advice.
  • Ensure maintenance and integration teams are kept up to speed and buy into design principles.
  • Understand and support the role of design manager (and if separate) design coordinator.

Manufacturers and suppliers

  • Prepare in-depth manual/instruction sheets on how to apply/use materials; check operatives understand what is required and that it is doable under site conditions.
  • Provide full downloadable information on the web.
  • Offer discounts for delivery to off-site consolidation centres; journey times more flexible and your deliveries will be faster away.
  • Could you offer support to constructors with elements of off-site prefabrication?
  • Offer training on your products and site advice on product installation/use issues.
  • Develop a list of approved installers; train them and monitor their work, in order to provide customer satisfaction and avoid loss of reputation.

7. Conclusions

A. The problem of ‘defects’. The issues of ‘defects’ is (like the construction process as currently practiced in the UK) complex and not susceptible to resolution by complying with a brief set of rules. Nevertheless, this project has been able to deliver guidance on both the nature of defects and how to deal with them and also pointed out influencing factors which should reduce their occurrence and impact.

Action by all parties is required to improve the situation. A Keisen approach is required.


B. A cultural problem, rooted in procurement methods.
Few would argue with the idea that the underlying issue is one of culture, but intertwined with that has to be the procurement and delivery environment and mechanisms which affect what people are motivated and able to do and how they therefore interact.

Based on experience, the project has offered guidance on what works best.

C. A people problem.
Finally, the team were all agreed that for a successful project the first choice would be to work with people you know and trust. Anyone laying down rules for procurement whether by government or a private organisation) would do well to contemplate on that.

People issues (including their motivation, expectations and skills) underlie the solutions to the problem of defects.

Appendix A: the study team

John Caves, TfL (LUL)
Peter Clarkson, Skanska
Geoff Cross, David McLean Holdings
Frances Gard, Kier Western
Alan Gilbertson, CIRIA
Peter Moore, BAA
James Pargeter, Drivers Jonas
Bob Peake, Metronet
Colin Ratcliffe, Bluestone (now Morgan Ashurst)
David Sturgeon, Lloyds TSB
John Tygier, Sheppard Robson
Simon Vilarasau, CIRIA

The team consulted with Dave Hewitt of MJN Colston on issues relating to building services package supply chain issues.

More information about the activity of the organisations of team-members is provided in Appendix D.


Appendix B: core reasons for defects
The team found the defect issues presented in Appendix C useful, but they didn’t encapsulate the core reasons for things going wrong (although ‘People’ was one of the categories). Another way of looking at the picture was therefore developed, concentrating on the underlying factors, as shown below. This enabled the team to identify higher-level responses and to identify where there was the best opportunity for change.

Ref

Core reason

Opportunity for control*

Response activities

1

People - competence and frailties

*****

Train, select, systems, processes, culture

2

Procurement route

*****

Select, manage

3

Environment

**

Recognise, understand, allow for

4

Constraints

***

Recognise, understand, allow for

5

Resources - time, £, stuff

***

Recognise, understand, allow for

6

Team dynamics

****

Selection, leadership, building ownership/respect

7

Change

****

Recognise, understand, respond

*Note: more stars denote more opportunity for control.

Each 'core reason' could affect any individual issue on a project to varying degrees.

Our assessment was instinctive and further work could yield interesting results.


Appendix C: categories of defects

The members of the team created this list at their first workshop and it stood up well over time. Some used it in analysing projects, to categorise defects and to look for patterns on their projects.

The high-level features identified were:

Within each high-level feature were a number of issues. The large number of issues to be controlled provides an insight into the magnitude of the subject.

Front-end

  • Project definition (Money+Time+Quality) mismatched.
  • definition/opinion of quality not aligned.
  • Gaps in scope.
  • False defect (client expectation).
  • Value engineering - over zealous/disruptive.

Design (both overall and package design)

  • Design doesn't/can't work or isn't fit for purpose.
  • Specification issue inc. incorrectness or wrong quality or incompatibility of materials/products.
  • Lack of information or incorrect/silly details for site or "buildability" problems found on site.

Supply

  • Manufacturing defect.
  • Late delivery.
  • Damage in transit.

Site management

  • Poor supervision/inspection.
  • Incorrect setting out/dimensions.
  • Defects due to integration issues.
  • Poor integration between trades or disciplines.
  • Working out of sequence.
  • People unable to work properly due to work coordination problems.
  • Lack of co-ordination of end product (supplier design) with the works generally.
  • Wrong equipment procured.
  • Inadequate access, lighting etc provided.
  • Package interface issue.
  • Tolerances clash/gaps.
  • Work carried out in dirty environment.
  • People working to superseded information.
  • Work not completely commissioned/tested/certified.
  • Reworking necessary due to poor sequencing.
  • Protection provided proved to be inadequate.

Site operation

  • Work not carried out/unfinished.
  • Poor/defective/out-of-tolerance workmanship.
  • Don't understand quality level/lack of benchmark.
  • Manufacturers recommendations not followed.
  • Parts damaged or Installed incorrectly, bits left out (but not visible afterwards)
  • Built in wrong place.
  • Defect caused by rectifying other defect.
  • Causing reworking by others e.g. damage to "finished" work by another trade/ installation.
  • Casual damage.

Variation

  • Client request/additional work (late instruction).
  • Late change not fitting with design thus far/badly thought through (implications not fully appreciated).
  • Architect/engineer change of mind.
  • Late decision led to hasty work.
  • "Aesthetic" dispute/change of mind.
  • Late value engineering.

Performance failure

  • Things that worked that stopped working – e.g. door closers, M+E etc.
  • Engineering (design) issue becomes apparent.
  • Material failure.
  • Structural failure.
  • Was "OK" but faded or warped etc.
  • Suspect substrate works (floors/walls/ceilings) becomes apparent.

Documentation/Certification

  • Compliance issue (certification).
  • Lack of evidence to support compliance.
  • Documentation issue (O+M, CDM).
  • Test result/failure.
  • As builds wrong.
  • Safety authority looks and doesn't approve it.

End user

  • User error/mis-use.
  • Damage by client/user/third party.
  • User gets involved and doesn't like it.
  • Left lying fallow and deteriorates.
  • User not trained/doesn't understand how to operate.
  • Not correctly maintained/cleaned.
  • False defect.

People

  • Poor performance by particular individuals.
  • People changed, leads to misunderstanding.

Acts of God

  • "The weather gods" (beyond what should be foreseen!)
  • Market conditions change rapidly.
  • Vandalism by persons unknown.

Appendix D: Activity in participant organisations
John Caves, TfL (LUL)

Peter Clarkson, Skanska

Geoff Cross, David McLean Holdings: Managing the delivery of projects with zero defects using the DMCL self-certification process

Frances Gard, Kier Western: Target Zero’ defect management

Peter Moore, BAA

James Pargeter, Drivers Jonas

Bob Peake, Metronet

Colin Ratcliffe, Morgan Ashurst: ‘Perfect Delivery’

David Sturgeon, LloydsTSB

John Tygier, Sheppard Robson


Feedback

If you have any feedback about the Towards Zero Defects (TZD) Toolkit, email Alan Gilbertson.