Looking At The Studies Conducted In Risk Assessment Construction Essay

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3.1- introduction:

There are different studies conducted in risk assessment, general and the causes of different types of delay in the construction process. The surveys conducted depended on questionnaires and contact by telephone with some contractors, consultants and clients. It outlined about 50 different main causes of delay in construction projects. There are assembled delay factors which are divided into about se.

ven groups dependent on the difference of importance to different parties of the project. The research discusses the delay in constructing different types of building projects. There are about fifty causes which affect the duration limit of the project. The most important causes of delay can be related to the client involvement, contractor performance and the project planning and design. Some important causes can be financial problems or the increasing cost of the materials. The delay can be a result in the management of the project, making decisions or approvals by client. Some construction delays can be a result in difficulties obtaining work permits or coordination problems.

Planning is a principle function in construction management and programme. It is a key tool in the management of the construction process. Some plans don't turn out as expected and this is especially the case in construction work that is delayed. Delays due to weather and waiting for the instructions from the owner or consultant are just some of the many things that can happen. The most important of construction planning issues is to ensure the planning process includes elements to control the process, duration and quality (construction planning, programming and control).

Time, cost and quality are the three common concerns of construction project management. There are many factors related to time and costs overruns and vary along with types of project, location and the size of the project. Construction projects and their complex features have attracted the interest of many researchers (Long Le-Hoai, Young Dai Lee, and Jun Yong Lee 2008).

3.2- the relationship between Time, Cost and Quality

Construction Management concept is strongly embedded in the building procurement system. According to (P.A. Bowen and Associate Professor K.S. Cattel p1) Ireland (1983) who argues that, time, cost and quality are client's principal objectives in any construction project. Time, cost and quality are incorporated in the management system of any construction projects. Figure-3.1 shows the time, cost and quality triangle works and relationship between them on the principle that as more emphasis is placed on one element, less is placed on the others.



Figure3.1 above illustrates the relationship between time, cost and quality as three primary forces in a construction project. Time is the available duration in the contract to deliver the construction process, cost represents the budget of the project or available resources. The quality represents the fit-to-purpose that the planned project must achieve successfully. Each one of these factors in a normal situation is fixed but the other two will vary in inverse proportion to each other. If the time is fixed then the quality of the final work will depend on the cost and the available resources. On the other hand if the level of quality is fixed, the project cost will be dependent on the available time. There are only three options in some situations in a construction project:

increase time - delay the project to give the contractor more time to achieve the functionality

increase cost - recruit, hire or acquire more labours to undertake the extra work

Cut quality - in this option, the contractor has to trade off some non-essential requirements to achieve new requirements


The client is the decision maker however: he has an unsavoury habit of trying to own all these three factors but he does not have all the information available sometimes to dictate these three factors (Cost, quality, time - choose two p1)

3.3- Delay and disruption:

Both delay in construction projects and disruption are common features in the final quality and cost of the project. According to Latham and Egan reports-Rethinking construction (1998), highlighted that "widely seen as unpredictable in term of delivery on time". While the improvement in construction management, it is around 40% of construction projects still finish late.

3.3.1- Delay reasons and disruption in construction projects

The majority of construction projects which finish late are likely to be delayed by the period of time which extended the duration of the project. there are some notable examples in the United Kingdom over recent years such as; the building of Scottish parliament and the new Wembley stadium. According to NAO 2003, the Scottish Parliament 2004, These two buildings of Scottish parliament and Wembley stadium were overrun the planned programme of construction. Finding delay reasons in major construction projects is not too easy. Each one of the contractor, client or the consultant will have his prospective view of the reason of project delay. Delays in construction projects can be in the flow of design information or the dispute between the contractor and the client. (NAO 2003, the Schottish Parliment 2004)

The reasons of delays and disruption in construction industry on normal projects can include:

Where the contractor and the client are at fault such as;

Incomplete design at commencement on site

Delay caused by the flow of project design information

Variations and changes between the contractor and the client in the scoop of the work

Discrepancies in the documents of contract

Where the contractor is at fault such as;

If the workmanship is poor quality

Inadequate construction process planning and programming

Under resourcing of site operations

Accidents during construction process on site

Where no one is at fault such as;

The conditions of Unforeseen of construction materials cost

The supply of materials

External factors for example Fire or explosion.

Weather condition which effect the efficiency of labourers

The delayed projects have implications for both the contractor and the client. The client or owner is able to enjoy the new project when anticipated but the delay of his or her orject can lead to loss the expected utility. However; if the contractor is not the site manager he cannot be able to release the project manager or site manager and other resources for new project as programmed or planned leading to any delay on the project or the other projects. The delay can increase the cost of the project for running the site establishment for longer than initially planned.

(Construction planning, programming and control p 359)

3.3.2- Types of delay

There are different meanings of delay in construction industry:

Delay event- this type means if some circumstances happen which lead to delay. The delay event can be the contractor responsibility or can be beyond the power of either party such as if the city council stopped any construction process in the area for some reasons.

Culpable delay-this type of delay is a contractor's fault. This is also not acceptable and non-excusable delay such as; stop working without any strong reason which resulted a project delay.

Non-culpable delay- this type of delay is not a contractor's fault where he is delayed through owner or consultant fault. This delay can be called excusable delay.

Concurrent delay- this type of delay can be happen where two or more reasons events happened at the same time. These reasons of project delay can be fault of both contractor and client at least one of the delays caused by the contractor.

Neutral delay- this type of delay can be caused by factors beyond the control of either of the contracting parties. This type does not mean that neither party bears the risk such as;

Natural delay at contractor's risk:

Not acceptable weather for working

Lat of material delivery

Delay by the chosen sub-contractor

Natural delay at client's or owner's risk:

Exceptionally bad weather

Discover some mistake in the project design on the site

Transportation problem which can affect the site work

(Construction planning, programming and control p 361)

3.3.3- Time Extensions

Delay issues in construction industry are dealt with in standard contracts of construction projects through specific clauses dealing with:

Time extension of construction project beyond the control of contractor

Procedures for the contractor for extension the duration of the project

Procedures for the administrator of the contract for consideration to the contractor's application

According to (Construction planning, programming and control p 361), said that" There are usually no similar provisions dealing with disruption and therefore the contractor may have to rely for his entitlement upon terms likely to be implied into the contract by a court. Such implied terms may include the employer's undertaking not to hinder or disturb the contractor's execution of the work. The contractor may also seek to rely upon express contract conditions entitling him to loss and expense by applying for additional payment should the regular progress of the works be effected by specified relevant events".

In any event, the contract administrator's responsibility is to monitor the performance of construction process and make decisions if any delays happen. Under JCT 05 Standard Building Contract, the project designer is required to:

an extension of time should be Granted to the contractor to complete the work where the completion of the work is likely to be delayed (clause 2.28.1)

the extension time granted should be state for each relevant event (clause 2.28.1)

Review the situation of construction which affect the completion date

Where the contractor is not proceeding the construction process regularly and or the work are suspended, give notice to the contractor (claouse 8.4.1)

The date of completion the project should be determined once the construction process are complete and everything relevant should be taken into account (claouse 2.28.5)

(Construction planning, programming and control p 361)

3.4- delay analysis

Under the common standared forms of contract, it falls to the contract administrator, architect or engineer, to determine whether or not the contractor is entitled to an extension of time under specific circumstances. For instance, under the JCT 05 Standerd Building Contract, a decision has to be made whether a 'relevent' has happend and what the contractor's entitlement will be. Such decision need to be made when it becomes apparent or likely that the contract completion date will not be met.

When delays occur on project, the contractor parties will be keen to ensure that they recover their due entitlement under the contract such as an extention of time, loss and expense or liquidated and ascertained damages. It is frequently the case that agreement cannot be reached and adjudication, arbitration or even litigation may follow. Not surprisingly, each of the parties will want the best statment and to this end will 'argue thier corner' as best they can.

The quastion is a simple one:

What was the couse of the delay and

Who bears the time and money risk?

Finding the right way to get the answer is not to easy though becouse, whilst there are a number of appropriate mythologies available, much depends on the rigor of the investigations undertaken and the skill of the analyst who must determine why a project as delayed.

According to farrow (2006), the techniques used may be categorised as either therotical or actual, although it is recognised that a degree of theory is present in both theoretical and factual techniques due to the etent of personal judgment and interpretation of facts required in most analyses.

When delay or disruption occurs, the particular conditions of contract for the project must be referred to in order to determine whether any relief is available for the event in question.

(Construction planning, programming and control p 368)

3.4.1- Schedules used in a delay analysis

There are different types of schedule which can be used for determine the impact of delays in construction projects. These types are as project construction planned, adjusted, as-built and entitlement schedules. As project construction planned schedule of the project represents the original plan for completing the work which is prepared by the contractor. This schedule does not show the progress of the project but shows the planned activities by using the critical paths method start and finish dates of the project.

The adjusted schedule reflects how the as-planned schedule has been impacted and the construction project effected such as; change the orders of the activities and delays of the project. The project starts by the as-planned schedule but the adjusted schedule mentioned delays in the schedule. In The adjusted schedule, the critical path(s) and the starting construction of the project and finish dates can be different from the as-planned schedule.

(Construction Management and Economics p377)

3.4.2- Delay analysis procedure

The as-planned schedules or the adjusted schedules should be used to quantify the delay period and causes in the project. The schedule should be updated after delays were inserted in the schedule (McCullough, 1989). The critical path methods or bar charts are scheduling techniques which can be used to estimate the delay period based on the specific impact. In the beginning of any construction project, the construction process schedule will be developed by the best achievable estimating and the activities sequence. During the construction process period, the new conditions will update the schedule of the project.

(Construction Management and Economics p377)

3.4.3- Delay analysis techniques currently in use

The majority of delay analysis techniques are using the as-built and as-planned schedules to analyse the delay in construction projects. These schedules have been used to determine the impact of the delay in the. These techniques are (Alkass et al., 1991, 1993; Wickwire et al., 1991; Reams; 1990; Leary and Bramble, 1988):

(Construction Management and Economics p377) Global impact technique

This technique is to record and depict the causes of delay and the impact. The delay period and disruptions should be drawn on a bar chart. The delay period from start to finish dates is determined for each activity in the project and the overall delay of the project will be calculated to be the total delay period of the project duration.

(Construction Management and Economics p380) Net impact technique

The net impact technique focuses on all delays factors on a bar chart. This technique is used for all change orders of project activities and delays by using the as-built schedule. The main different between the as-planned and the as-built in this technique is that the completion dates of time extension is required.

(Construction Management and Economics p380) Adjusted as-built Critical Path Method technique

This technique based on the Critical Path Method to develop the as-built schedule. The events of delays should be drawn as construction tasks and linked to other specific construction activities. The critical path(s) will be identified two times. one in the as-planned schedule and the other time will be at the end of the project.

(Construction Management and Economics p380) `But for' or collapsing technique

`but for' technique is called collapsing technique and uses the Critical Path Method format of scheduling. This technique entails one party taking of the schedule as-planned and injecting all construction project delays which will be accepted for their responsibly. The schedule will be updated and revised to meet the completion date of the project to compare with the as-built schedule.

(Construction Management and Economics p382) Snapshot technique

It can be used this technique to estimate amount of delay's period which has been occurred in the project and when the cause(s) of the delay happened. This type of techniques is based on the as-planned schedule and as-built schedules which have applied during the construction process. The overall duration of the project will be divided into several of time periods.

(Construction Management and Economics p382) Time impact technique

This type of technique examines the impact of the project delays at different times during construction process. This technique is similar to Snapshot technique but the main difference is that the time impact technique focuses on the specific delay event but does not focuses on period of time which has many delays events.

(Construction Management and Economics p384)

3.4.4- Assessment of the delay analysis techniques

When dealing with delay analysis for construction claims, it is important that the technique used is a viable one. The techniques mentioned earlier range from simple date comparisons to tedious and time consuming detailed analyses, any of which can yield a wide variety of results. When the ultimate goal in preparing a delay analysis is to present the results in court as supportive documents, it is necessary to ensure that the technique used is sound. In order to assess the different delay analysis techniques previously mentioned, each technique was applied to a common test case using Primavera Project Planner scheduling software (Primavera Systems Inc., 1991).

(Construction Management and Economics p377)

3.5- construction planning

The contractor has a project manager who assesses the resource capabilities levels and the needed of capacities to accomplish the construction project defined. Capability is the measure of the levels of a resource's skill, experience and performs ability. Project manager needs to consult with consultant who has experience with same projects to accurately determine the important resources.

Construction Project Management Handbook p3-4

3.5.1- Planning process

It is difficult to envisage the successful work of the construction project or the effective control of the time, cost or resources without planning. Planning the construction process is important to deal with the potential risks which can affect the duration of the project and device safe working methods to avoid any delay. It is known that throughout all stages of construction process or design 'fail to plan-plan to fail'. There are many reasons for construction planning such as;

To set and establish a realistic time, framework and construction standards to avoid any impact for the project.

To aid control during the construction process

To monitor the performance of the construction process in terms of the output, cost and time

To review the progress of the project and take action when necessary to avoid risks.

(Construction planning, programming and control p 130)

3.5.2- Planning the process of the project to control the project

When preparing the construction project programme, it is important that to process in order to develop a realistic construction plan and workable programme for the project. The experiance of the development and construction process is essential. The level of shown detail in the programme for construction process should be commensurate with the stage of the project under consideration. The duration of construction activity is based on the calculation or empirical data.

(Construction planning, programming and control p 139)

Planning of project requires a logical approach involving various steps or throught processes:

Getting a feel for the project

Establishing key project data

Establishing key activities or events

Assessing how long the activities will take

Establishing the sequence

Deciding which programming technique to use Getting a feel for the project

It is essential factor for the contractor or the project manager to get a feel for the project because a clear appreciation of the scale of the work in the project and complexity of the plans helps to trigger the natural human instincts of when things look right or wrong. These human instincts are based on the familiarity with the construction work and experience. It is important that to estimate the financial scale of the project but the experience identifies the value of the project or expenditure rate as being inconsistent with allowed time of the project. The following consideration help to get feel for the project:

Study the documentation of the project and drawings.

Visit the site to discover the effective external factors.

Assess the project scale and scope.

Assess the project value approximately

Consider the expenditure rate such as the relationship between tie in cost.

(Construction planning, programming and control p 139) Establishing key project data

The project parameters will be determined by the key data establishing. Some of these can be established by the client and his consultant and conveyed to the contractor in the documentation of the tender. They will include:

The date of Project start and finish.

the completion dates Sections or phases

Holiday periods

Commissioning handover

(Construction planning, programming and control p 140) Establishing key activities or events

Determine is the key of tasks or activities to be carried out together with any essential events of the project which should be included in the programme. The construction project Activities are tasks should be done which have time value. Planning permission Obtaining is one of the activities because it can take several months or even years to be completed. Events are parts of the time by which things must happen and have no time value such as; the start of construction process is an event which triggers a series of project activities which do have a time value. Assessing how long the activities will take

Duration assessment of construction project activities is not an exact science. During the early stages of the project when available only little detailed information but the great deal of reliance should be placed on the experience. the calculations of duration of the project can be performed by the consideration of the relationship between the work quaity and the the rate of production anticipated such as;

Quantity/ output per hour = Hours

Hours/ number of hours per days (8) = days

Days/ number of days per weeks (5) = weeks

(Construction planning, programming and control p 141) Deciding which programming technique to use

There is no strict rule to choose the programming technique which should be used. It is needed to be considered depending on the complexity and the size of the project. The personal preferences or stipulations should be in the contract documentation.

The easiest technique to use is bar charts but they give sometimes misleading results because there is no strict logic applied on this technique or programme. The best way to use this technique are linked bar charts, arrow or precedence diagrams to solve this problem. The repetitive construction projects like housing, the line of balance can be preferred. for tunnelling projects, roads the diagrams of time- chain age can be the best application to apply.

(Construction planning, programming and control p 142)

3.6- control the time in construction projects

Planning the construction process is one of the functions of management the project but the programme is a key tool in the construction management. However, some plans overrun the expected time and this is especially the case of work in construction. Unexpected ground conditions of construction site, delay due external factors such as weather or waiting for instructions from the client or consultant are just some many different reasons which effect the duration of the project can be happened.

It is so important that to ensure the planning process contain the elements of duration control and this plan can be monitored in the current circumstances of the project. Construction process activities can have to be arranged or require additional resources to cope with difficulties factors which can impact to the performance of the project. This can be the role of the construction contract programme which both the contractor and client contractor can use for monitoring what is happening.

The contractor will normally have to complete his work on or before the completion date of the project. If the contractor fails to achieve his project on the proposed time without valid reasons he may suffer the deduction of the contract payments depending on the agreement. This is disadvantage for the client because his project will still be late and therefore the contract administrator will use the programme to check that the contractor performance is progressing satisfactorily. If the construction processes are not going according to the plan, the project designer or the supervisor of the project will point it out at the monthly meeting to ask the contractor what he will do about it.

(Construction planning, programming and control p 348)

3.6.1- Time for completion

The majority of contract standards conditions have similar provisions such as; time for completion the project. The contract will contain:

Site possession date

Date(s) for specific sections possession of the site

completion date for of the work

completion date for all sections of the works

The period of time for deferment of possession can be stated and the employer can delay handing over the construction project site to the contractor without contract breaching. The project contract states the rate of agreement of liquidated and damages of the materials for the whole sections of the construction process. The client can charge the contractor in the event of late completion of the contract.

(Construction planning, programming and control p 348)

3.6.2- The contractor's programme

The majority of contract standard forms, it is required from the contractor to design a programme for the project to state that how he can plan, organise and schedule the construction project. Such as;

JCT05 standard building contract- clause 2.9.1 master programme

Two copies of the programme for works execution as soon as possible after the signing the contract

Two copies of the updated programme for project construction following an extension of time under clause 2.28.1

JCE7- clause 14, programme

The programme is showing the order in which the contractor is going to do in the project within 21 days of contract award.

The general description of the project and, arrangements and the methods of construction are at the same time

programmes revision where the actual progress varies are from the accepted programme

The details of methods of the construction process including the details of temporary works such as; scaffolds, framework and flatwork to use it together with related structural calculation

NEC- Core clause 3, accepted programme

Key dates of the project include starting date of the construction process, possession, partial possession and the completion dates of the project.

The methods statement for each operation of construction shows the plan of the equipment and resources

The order and timing of the construction process

Provisions for float, construction time period, risk allowances, the requirement of health and safety requirements and contractual procedures

programmes Revision are showing the actual progress of the construction process for each operation and its effect on remaining work

The effects of compensation events like, employer risk delay and matters which give early warning and how can the contractor plan to deal with these issues.

The conditions of JCT, IGC AND NEC are vary as to the detail. The contractor will show sufficient detail so that the architect of the project, civil engineer or administrator of the contract can monitor the construction process and make informed judgments about any time extension and so on the work proceeds in the project.

(Construction planning, programming and control p 349)

3.6.3- Early warning system

The majority of success construction projects are often related between the main project supplier, contractor and the subcontractor. Bar chart displays the connection between commencement and procurement of process in the site which this technique has become an essential part of construction planning. This is to ensure that the dates are met with respect to the requirements of project design and commencement delivery of construction works on site.

Early warning system in construction projects were developed by John Laing in the mid 1960s and extensively used. This system works because it is simply application and ease of monitoring such as; the users are allowed to develop the letters and own symbols to denote information requirements. The New Engineering Contract (NEC) (clause1- general) highlights the early warring requirements. The responsibilities are on both the project manager and the contractor to give an early warning to the client on any matter which can affect the performance of the project or make any delay of project completion.

(Construction planning, programming and control p 350)

3.6.4- Progress and delay

The contractor should provid a regular updates to the programme and proceeds regularly with the construction works. The contractor of the project is free to complete the construction process on the time or before the contract completion date but the he does not suffer during the project duration any hindrance or prevention from the client, contract administrator or the supervisor. However, the contractor can be delayed in his project for one reason or another either due to:

A contractor risks in duration of the project such as;

Delay caused by the sub-contractor

External factors such as weather delays

shortage of Labour or plant

Owner or client risks in the duration of the project such as:

design changes by the owner within construction period

Variations between client and contractor

Late of site possession.

Exceptionally adverse weather

Some other reasons

This does not mean necessarily that the completion of the project will be delayed but the contractor solve the problem by making up the lost time by rearranging the work sequence to be more efficiently or by working faster by increasing the number of labourers. However, delay in construction project is likely, and this is due to the project manager risk event. Construction project contracts provide a mechanism for the contractor to be granted the time extension of the project.

(Construction planning, programming and control p 351)

3.6.5- Progress recording

The purpose of recording the progress of construction process is to provide a weekly or monthly report of progress to assist the contractor and the project manager to inform the monthly progress meeting with the project client, contract administrator the architect. Procedure for recording progress

The contractor or the project manager will monitor the performance of the construction process on site. The monitoring process can be weekly or monthly report about the progress and recording any factor can effect to the project. This progressing report should be prepared and completed two days before the review meeting and should include a visual progress about the applied programme.

The summary of the report should highlight the concern operations in the process. Comments should include relating of the performance of the construction process to be taken in order to get the contract or the sub-contractor back into the planned programme. The Reasons of construction delays can be indicated especially where the delay factors have been caused by variation to the contract of the project, late receiving the information or delays by the chosen sub-contractors. Progress recording procedures in practice

Laptop computers can be issued in some medium or large construction organisations, to senior site staff. Project manager will have access to the master programme of the construction process and can have attended to the training programmes in the company to learn how he can record the progress on site. Thus, project manager will be able to progress record the construction's master programme of the project and able to email to his contracts manager in the company the important information to discuss about it in the progress meeting in the head office.

(Construction planning, programming and control p 354) Progress recording on the bar chart

Recording the progress of construction project has different ways on the bar chart which can be weekly or monthly intervals. The responsibility of progress recording can be delegated to the construction planning engineer on huge, large scale projects, or the project manager in the site on small projects. In the other hand, the department of construction management and planning in the company can act as an independent progress monitoring depending on visiting the project from time to time for preparing a detailed report of the project performance. This procedure is one of contractor responsibilities and management techniques of the site management reporting procedures. Progress recording on the colour coding

It is important factor within the company to record the construction progress and performance by colour coding on bar chart such as; green colure shows the actual time expended on process and red colure can illustrate the completed operation's percentage. Progress recording by computer

There are a lot of software packages allow the user to record the construction progress and performance by using computer. This is usually done depending on the percentage of each completed operation, which involves the project manager only entering the percentages and pressing the analysis command and leaving the rest to the computer. Progress recording by earned value

The physical progress on construction project contract measures according to the received value of completed operation. This can be estimated by plotting the forecast value for the contract depending on the earliest and latest time of the activity. It is important that to use the free time in the activities which are non critical to create a control envelope. In other hand, keeping to the construction process period as planned by the critical activities of the project. The monthly site progress report

It is comment practice for an operational progress report to a company the marked up bar chart. The report of progress is written by the site project manager and can be produced by one of the usual software packages of project management. The report highlights the project's performance and progress position activity by activity.

3.7- previous international studies about construction delays

Many researchers have studied the causes and few researchers have studied the effects of project delays in the construction industry. We have broken the studies into two parts: (1) Studies on causes of delay and (2) Studies on effects of delay.

3.7.1- Studies on causes of delay

There are many general causes of construction project delay. Kumaraswamy and Chan have conducted a survey to evaluate the importance of the 83 potential factors of delay in construction projects in Hong Kong. They have found five important and principal factors which are;

Poor supervising and management of the project

Topography having unforeseen effects on site conditions

Slow decision making

Client and contractor dispute

Work variations

Kumaraswamy and Chan found that there were different perceptions on the causes of delays depending on the different groups of participants in building construction and works of civil engineering. They have suggested that many different groups of industry might direct effect for delays to other groups.

Al-Momani has investigated the causes of construction delay for 130 projects in Jordan. The principle causes of project delay were related to architecture, user changes, environment, the conditions of the site, late deliveries, economic situation and quantity increasing. It is suggested in the study that special attention to factors can help industry practitioners in minimising disputes of contract. Delay of a project is related to failure and ineffective contractor performance.

Ubaid has discussed the contractor's achievement as one of the principle causes of delay in construction projects. There are about 13 principle measures that were considered which are related to contractor capabilities and resources. Chang (2002) identified deepening on four cases studies in construction project documents. He found that the reasons for increasing the cost of the project and planned schedule was based on the problem of the design of the projects.

According to the conducted study by Ogunlana and Promkuntong on construction delays in Thailand, the problems were founded in construction industry in non developing economies like Thailand can be:

Shortages of resources supply in construction industry and infrastructure

Delays can be Caused by owners and engineering consultants

Delays Caused by inadequacies of contractors.

They have recommended that there should be concerted effort between the economy managers and the associations of construction industry to provide the infrastructure for efficient project management.

According to Mansfield he has identified that, there are about 16 major factors which caused delays in Nigeria. He has used in his survey a questionnaire and he carried out with some contractors, consultants and owners in Nigeria. He found that the delay causes in construction projects Nigerian were related to:

The regularity payment by the owner

Poor contract management

Shortages in construction materials

Inaccurate estimation

fluctuations of materials price

(Murali Sambasivan *, Yau Wen Soon 518)

3.7.2- Studies on effects of delay

Aibinu and Jagboro [1] studied and evaluated the effects of construction delays on project delivery in Nigerian construction industry. They found that the six effects of construction delay were: time overrun, cost overrun, dispute, arbitration and litigation and total abandonment. The questionnaires were sent to three groups of construction practitioners: quantity surveyors, architects and engineers, and contractors.

Manavazhia and Adhikarib [13] conducted a survey to investigate material and equipment procurement delays in highway projects in Nepal. Delay in the delivery of materials and equipment to construction sites is often a contributory cause to cost overruns in construction projects in developing countries. An assessment of the causes of the delays and the magnitude of their impact on project costs were also made. The survey method was used in conducting this research involving 22 highway projects. The main causes of material and equipment procurement delays were found to be (in rank order) organizational weaknesses, suppliers' defaults, governmental regulations and transportation delays. However, the actual impact of these delays on project costs was found to be on average, only about 0.5% of the total budgeted cost of the projects. Among materials, delays in the supply of aggregates and equipment were found to occur most frequently.

(Murali Sambasivan *, Yau Wen Soon 519)