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A detailed literature review was carried out to identify the previous studies in the research area and found the major causes and effects of delays in projects in Sri Lanka and other counties. Then, a careful identification of the factors related to the study were done and a survey questionnaire was developed to assess

the perceptions of contractors and clients who were involved in construction of medium scale water supply projects on the relative importance of causes and effects of construction delays. The questionnaire consisted of four parts; part I- respondents’ details, part II–causes of delays, part III–effects due to delays, part IV– mitigation actions. The first part of the questionnaire requested the respondents’ general details while the second part of the questionnaire consisted of thirty nine causes of delay that were categorized under seven major groups:

i. Project related: Inadequate project duration, Improper contract formulation (large Nos. of contracts for a single project, intake civil construction work included in a pump contract, etc.),type of project bidding and award (tendency in awarding the contracts to lowest bidder)

ii. Owner/consultant related: Delay in progress payments by owner, delay in handing over the site to the contractor, delay in approval of shop drawings and samples, delay in inspection and testing of works, Inadequate Liquidated damages, too many change orders, slow decision making, poor contract management of owner/consultant.

iii. Contractor related: Contractors financial difficulties, mistakes during construction and rework, shortage of project staff with

required experience, Poor

coordination/communication by the contractor with other parties, Ineffective planning and scheduling of project by contractor, improper construction methods implemented by contractor, delays in sub contractors’ work, insufficient delegation of power to the site management team. iv. Design related: Delays in producing

construction drawings, unclear and inadequate details in drawings, mistakes and discrepancies in drawings and bills of quantities, inadequate specifications for materials.

v. Materials related: Shortage of construction materials in market, changes in material types and specifications during construction, restrictions on issuing permits to transport materials, rejection of imported materials due to non-compliance with the contract specifications.

vi. Equipment and Labour related: Frequent equipment breakdown, shortage of equipment and hiring delays, low productivity and efficiency of equipment,

low productivity level of workers, shortage of labour, labour union actions.

vii. External factors: Inclement weather

conditions, delay in obtaining permits, services, etc. from local authorities and other organizations such as electricity board, traffic/security problems, changes in government regulations and laws, rules and regulations of Road Development Authority(RDA), Provincial Road Development Authority (PRDA) and local government authorities (PS) on road excavation work approvals.

The third part of the questionnaire consisted of the effects due to delay checklist: Time overrun cost overrun, dispute, arbitration, litigation, total abandonment, funding difficulties, delay in commissioning other related projects and develop unfair relationships with other organizations such as RDA, PRDA, PS, etc. The last part of the questionnaire is for getting the respondents prescriptions to reduce delays in construction of medium scale water supply projects. For each cause/effect two questions were asked: what is the frequency of occurrence for this cause? and what is the degree of severity of this cause on project delay? Both frequency of occurrence and degree of severity were categorized on a four point scale. Frequency of occurrence was categorized as: Rarely, Sometimes, Often and Always. Similarly, degree of severity was categorized as: Little, Moderate, Great and Extreme.

In Sri Lanka, almost all the medium scale drinking water supply projects are carried out by the National Water Supply and Drainage Board and the contractors are involved in these developments. The questionnaire was distributed among the professionals of the above two groups and the sampling method used in this study was convenience and snowball sampling that comes under the class of non-probability sampling techniques [7].

3.1 Ranking of delay factors

The ranking of causes and effects of delays from the viewpoints of three parties involved in construction projects; owners, contractors and consultants can be done using three indices; frequency index, severity index and importance index [11]. The similar method was applied in the study and the following equations were used for the calculation of three indices. Frequency index (FI) is a formula

Category Questionnaire sent Hand delivery Regualr mail Via Internet Total Client Nos. of participants 36 15 21 72 Nos. of respondents 28 12 3 43 Response rate% 77.78 80.00 14.29 59.70 Contractor Nos. of participants 35 15 20 70 Nos. of respondents 30 4 6 40 Response rate% 85.71 26.67 30.00 57.14 T otal Nos. of participants 71 30 41 142 Nos. of Respondents 58 16 9 83 Response rate % 81.69 53.33 21.95 58.5 used in the study to rank causes of delay based on frequency of occurrence as identified by the participants. :

(FI) (%) = ∑a (n/N)*100/4 (1)

where, a is the constant expressing weighting given to each response (ranging from 1 for rarely up to 4 for always), n is the frequency of the responses, and N is total number of responses. Severity Index (SI) is a formula used in the study to rank causes of delay based on severity as identified by the participants. (SI) (%) = ∑a (n/N)*100/4 (2)

where a is the constant expressing weighting given to each response (ranges from 1 for little up to 4 for severe), n is the frequency of the responses, and N is total number of responses. Importance Index (IMPI) of each cause is calculated as a function of both frequency and severity indices.

(IMPI) (%) = (FI) (%) *(SI) (%) (3)