Types And Causes Of Construction Delays
This chapter gives an idea of what construction delays are, how are they defined and what are their types and comparison of them. Delays can be seen differently from different point of views. Causes of delays and categorization of them in various international contexts are also discussed.
2.2 DEFINING CONSTRUCTION DELAY
A lot of work has been done before on construction delays and every author came up with his/her own definition.
Assaf and Hejji defined delay as “Time overrun either beyond completion date specified in a contract, or beyond the date that the parties agreed upon for delivery of a project slipping over its planned schedule.” (Assaf, Hejji, 2006)
Stumpf defined delay as “Act or event that extends the time required to perform a task under a contract. It usually shows up as additional days of work or as delayed start of an activity.” (Stumpf, 2000). And many similar definitions were given.
Therefore construction delays can be considered as time lag in completion of activities from a fixed time as per contract or they can be defined as late completion or late start of activities to the planned schedule or contract schedule. When project delay occurs it means project cannot be completed within stated time, which means there will be extensions of time required which will further result in fine, increased cost due to inflation, termination of contract, court cases etc. or combinations of above stated factors.
Delay can be seen as risk for the project and could be handled at inception stage or at least one can try to mitigate or minimize it. Risk is an integral part of a construction project; it is well known that no project is risk free. If risk is analysed at inception or planning stage it could be managed, minimized, shared, mitigated or accepted to give some good results. Delay can be considered similar to risk or a type of risk; as no construction project is free from delays, delay is also integrated part of construction projects. It depends on size of project as well. Therefore it is expected to analyse and manage delay in same fashion as risk.
Delays are often result of a mismanaged event which must have been managed in a systematic process so as to analyse the effect of that event on the project and how to minimize chances of further delay. (Keane, Caletka, 2008).
2.3 CATEGORIZATION AND TYPES OF CONSTRUCTION DELAYS
Before getting on types of various construction delays there is a major categorisation which is required to be understood. Construction delays can be delayed in some major groups as listed below.
El-Saadi (1998) categorized delay in four major groups.
Critical or Non critical
Excusable or Non Excusable
Compensable or Non Compensable
Concurrent or Non concurrent
Alkaas S., Mazerolle M. and Harris F. (1996) and Ahmed S.M. et al gave following categorizations:
Excusable compensable delays
Excusable noncompensable delays
Fig. 2.1 Classification of delay based on their various attributes. Nuhu Braimah (2008)
To achieve objectives of this dissertation and to consider delay as risk it is necessary to know about these types of delays and as per categorization in what category they lie. This basic knowledge helps in moving forward and determining strategies to mitigate these risks. Now in this part we will discuss these types of delay in detail:
2.3.1 CRITICAL AND NON CRITICAL
In simple words Critical delays are those which cause delay to entire project completion date while Non critical delays not necessarily affect the project completion date but affects progress. In all the projects delays are considered at the project completion date. Delays can be combination of small and big delays that occurred during the whole project. Therefore critical delays are taken more into consideration then noncritical delays.
2.3.2 EXCUSABLE DELAYS
Excusable Delays occurs due to events which are outside the control of contractor like heavy rains, storms, strikes, fire, client suggested changes, differing site conditions, change of government policy or their intervention, stakeholder intervention etc.
Alkass S. et al (1996) says that when there are excusable delays, contractor is entitled to time extension in case date of completion is extended. Such delays can also affect non critical activities which must be considered with more detailed analysis or adjustment of float time.
Excusable delays can be further classified in compensable and noncompensable delays.
22.214.171.124 EXCUSABLE COMPENSABLE DELAYS
As name suggests excusable compensable delays are those in which contractor is entitled for extra payment (compensation) i.e. monetary compensation and time extension as well. But decision that a delay is compensable or noncompensable is taken as per contract between client and contractor. Natural disasters or some reasons which are out of control are not considered. Example of such delay could be that client doesn’t allow access to site even after notice to proceed is given; other such delays which are due to client are compensable.
126.96.36.199 EXCUSABLE NONCOMPENSABLE DELAYS
Such delays are such where both contractor and client are not responsible for delay. Under such circumstances only time extensions are granted and no monetary compensation is provided. Such delays include act of God.
2.3.3 NON EXCUSABLE DELAYS
As name suggests these delays are such that they don’t have any excuse or no excuse can be given for them. They arise due to carelessness or actions and inactions of contractors and subcontractors. For such delays no time extensions and monetary compensation is given to contractor if it has affected whole duration of project. In such cases client is liable to get liquidated damages. Example of such delay could be constructing something wrong which is not given in drawings, not completing work on time, improper resource allocation etc.
2.3.4 CONCURRENT DELAYS
This is the most complex categorization of delay as it consists of two or more kind of delays regardless of their type which occurs at same time or overlaps some duration together. It is necessary to find out what type has caused overall delay in project completion. Therefore different factors like time of occurrence of delay, duration of delay, impact of them, float ownership etc. have to be considered carefully.
Alkass et al (1996) said that; Concurrent delays which contains two or more excusable delays results in time extension. When compensable and nonexcusable delays are concurrent a time extension can be given or delay can be distributed between client and contractor.
2.4 CAUSES OF CONSTRUCTION DELAYS
In section 2.3, categorisation of delays was discussed. Now in this section will deal with causes of delays. Lot of work has been done on understanding causes of delays. The two major categorization of delay causes one is Internal Cause another is External Cause.
Internal cause includes delays caused by parties involved in construction project like Client, Contractor, Designer, Consultant these are four major parties then Subcontractors, material suppliers etc. comes. From external factors it includes act of God, strikes, stakeholder’s dissatisfaction etc.
Assaf and Hejji (2006) reflected various causes of delays which occur in large construction projects. They had a field survey of 23 contractors, 19 consultants, and 15 owners and found out and reflected on 73 causes of delays under eight different groups. All those 73 factors are given in table below.
CAUSES OF DELAY
Original contract duration is too short.
Legal disputes b/w various parties.
Inadequate definition of substantial completion.
In effective delay penalties.
Type of construction contracts.
Type of project bidding and award
Delay in progress payment by owner.
Delay to furnish and deliver the site to contractor by the owner.
Change orders by owner during construction.
Late in revising and approving design documents by owner
Delay in approving shop drawings and sample materials
Poor communication and co-ordination by owner and other parties
Slowness is decision making process by owner
Conflicts between joint ownership of the project
Unavailability of incentives for contractors for finishing ahead of schedule
Suspension of work by owner
Difficulties in financing project by contractor.
Conflicts in subcontractors schedule in execution of project
Rework due to errors during construction.
Poor site management and supervision by contractor
Poor communication and co-ordination by contractor with other parties
Ineffective planning and scheduling of project by contractor
Improper construction methods implemented by contractor.
Delays in subcontractors work
Conflicts between contractor and other parties
Inadequate contractors work.
Frequent change of subcontractors due to their insufficient work.
Poor qualification of the contractors technical staff
Delay in site mobilization.
Delay in performing inspection and testing by consultant
Delay in approving major changes in the scope of work by consultant
Inflexibility (rigidity) of consultant
Poor communication and co-ordination by consultant with other parties
Late in reviewing and approving design documents by consultants
Conflicts between consultant and design engineer.
Inadequate experience of dsigner.
Mistakes and discrepancies in design documents
Delays in producing design documents
Unclear and inadequate details in drawings
Complexity of project design
Insufficient data collection and survey before design
Misunderstanding of owner’s requirement by design engineer.
Inadequate design team experience
Un-use of advanced engineering design software.
Shortage of construction materials in market
Changes in material types and specification during construction
Detail in material delivery.
Damage of sorted material while they are needed urgently.
Delay in manufacturing special building material
Late procurement of materials
Late in selection of finishing materials due to availability of many types in market
Shortage of equipment
Low level of equipment-operator’s skill
Low productivity and efficiency of equipment
Lack of high technology mechanical equipment
Shortage of labours
Nationality of labours
Low productivity level of labours
Personal conflict among labours
Effects of subsurface conditions
Delay in obtaining permit from government
Hot weather effects on construction activities
Rain effect on construction activities
Unavailability of utilities in site
Effect of social and cultural factors
Traffic control and restriction at job site
Accident during construction
Differing site conditions
Changes in government regulations and laws
Delay in providing services from utilities
Delay in performing final inspection and certification by a third party
Table 2.1 Causes of delays as per group Assaf and Hejji (2006)
Their work gave a broad view over construction delays and their causes. Though their classification is quite broad, but it gives a more insight to various causes.
Odeh AM and Battaineh HT (2002) presented following 8 major groups of construction delay.
Client related factors which include finance, payment of billed work, interference in work, slow decision making etc.
Contractor related factors include site management, improper planning, insufficient experience, improper construction methods, insufficient and unskilled work force etc.
Consultant related factors include contract management, improper drawings, approval of drawings, tests at site etc.
Material related factors include availability, quality and shortage.
Labor and equipment factors include supply, productivity, equipment availability, failure etc.
Contract factors include changed orders and mistakes and disagreements in document.
Contractual relationship factors includes, disputes, negotiation, improper management of information system, improper work breakdown structure and task responsibility matrix.
External factors like act of god, strikes, accidents etc.
Most of the work done in field of causes of delays reflects similar causes of delays and 8 major groups. They all gave recommendations related to these factors but very few scholars suggested to forecast delay in planning stage. Khalil and Ghaftly (1999) said delay is important issue. In order to manage it more properly and to mitigate them deep investigation to this area is needed. Having idea of frequency, extent and responsibility of delay can provide insights of early planning to control these factors and improve project performance.
2.5 PERSPECTIVE FROM DIFFERENT COUNTRIES
Work from Chan and Kumaraswamy (2002) from Hong Kong industry gives four major causes of delay in Hong Kong industry which are as follows:
Management related attributes
The above four factors were studied with their constituent casual factors to gain more insight and understanding of their significance. They were summarized in following figure:
Figure 2.3 Summary of principal factors affecting construction durations of projects
He gave another table comparing factors causing delay in construction projects in various economies. It gives an overview of common factors in these economies. It gives a clear understanding of various countries at once.
Factors Causing Delay
Countries where survey was conducted
Labour shortage/ Low labour productivity
Poor subcontractor’s performance
Variations (design change/ extra work)
Unforeseen ground conditions
Materials shortage/ late material delivery
Inadequate construction planning
Delays in design work/Lack of design information
Poor site management
Inappropriate type of contract used
Lack of designer’s experience
Table 2.2 Source: Chan and Kumarswamy (2001)
Ogunlana and Promkuntong studied and compared construction industry of Thailand and other economies. Study involved delays experienced in the High Rise Building construction projects in Bangkok, Thailand. According to them Resource supply problem were most acute problems of the construction industry in boom years. Project suffered delays due to inadequate supply of cement, technical personnel were overstretched, and demands from owners to do frequent changes etc. are the major causes for delay in developing economy.
Sabasivan and Soon (2007) conducted study of causes of delay in Malaysian construction industry. They conducted a survey and 150 participants were involved. They came up with 10 most important causes of delay which are as follows:
Improper planning of contractor.
Poor site management from contractor
Inadequate experience of contractor
Improper payments and finance from client
Failure and availability of equipment
Improper management information system
Mistakes during construction stage.
MAJOR CAUSES OF DELAYS
Assaf et al
Slow preparation and approval of shop drawings
Delays in payments to contractors
Changes in design/design error
Shortages of labour supply
Mezher et al
Owner had more concerns with regard to financial issues
Contractors regarded contractual relationships the most important
Consultants considered project management issues to be the most important causes of delay
Al-khal and Al-Ghafly
Cash flow problems/financial difficulties
Difficulties in obtaining permits
“lowest bid win first” system
Changes in orders/design
Unforeseen site condition
Koushki et al
Owners financial constraints
Owner’s lack of experience in the construction business
Faridi and El-Sayegh
Slow preparation and approval of drawings
Inadequate early planning of project
Slow decision making of owners
Shortage of manpower
Poor site management and supervision
Low productivity of manpower
Assaf and Al-Hejji
Change in orders by the owner during construction
Delay in progress payment
Ineffective planning and scheduling
Shortage of labour
Difficulties in financing on the part of contractor.
Chan and Kumaraswamy
Management related attributes
Ahmed and Azhar
Acts of God
Table 2.3 Summary of previous studies of the causes of delay in construction project some data from above table is taken from Sweis et al (2008)
A total of 73 factors and 8 major groups of causes of construction delays were identified through intensive literature reviews in order to consider maximum factors. These factors will be helpful in data analysis so as to forecast delay at planning stage and treat it as risk so that risk management methodologies can be implemented to delay so as to mitigate and minimizing it.
These eight major categories can be brought down as shown in figure.
Fig 2.4 Classification of delay groups.
All major 8 groups can be brought down to 2 major groups which are Internal and external causes. Internal is further subdivided in owner, consultant, contractor and resources. Resources are further subdivided in Material, equipment and labour.
Overall if we need to classify groups for the causes of delay 5 major groups covers all 73 factors they are Owner, Contractor, Consultant, Resources and External.
These causes and classification will help us to rank and treat delay as a risk at planning stage so as remedial measures can be applied. Though in spite of all studies and delay causes know till now it is hard to forecast delay because it’s very unpredictable, we can’t analyse frequency of delay due to some reason in a project. Sometimes external causes are so dominating that co-ordination of internal groups get disturbed and project faces delay.