Delay Analysis in Construction Project

Transcription

1 Delay Analysis in Construction Project Abstract Delay of a construction project is defined as late completion of the project as compared to the planned schedule. Construction delays are often result of miscommunication between contractors, subcontractors, owners and suppliers. These types of unrealistic exceptions are usually avoided by using a clean and efficient planning mechanism, which clearly specifies the work and timetable to be used. Delays in construction projects are quite expensive; sometimes they may result in severe damages to the involved parties. This dissertation focuses on study of core factors that are causing delays and analyzing the day-to-day records to minimize delays. The current study is undertaken on Construction of New District Jail in Kurnool District of Andhra Pradesh. The project is construction of 2 Nos. of Barracks and is scheduled to complete in 12 Months. The study is being conducted on various factors that were causing the delays in project. The causes, effects and the various methods on how to minimize the delays in the construction site are noted down regularly. Construction delays can be minimized only when their cause are identified in the construction site. The day-to-day data is regularly collected from site. Starting time, Finishing time, and duration is recorded in MS Project differentiating task and critical activity along with the delays caused and reasons for the delays. Using the input data and the Gantt charts generated by MS Project the delays in critical activity of the project are analyzed. A questionnaire is prepared listing out various factors contributing to delay under different categories based on observations at construction site and from several journal papers as reference. The views on the same from various parties involved in a project like the builder/developer, contractor and consultants are sought in the questionnaire. Each factor is given a weight-age arrived at using filled-up questionnaires, using, which the most influential factors are identified Keywords Delays in construction project, causes for delays, impact of delays on Construction project. I. INTRODUCTION In construction, the word delay refers to something happening at a later time than planned, expected, specified in a contract or beyond the date that the parties agreed upon for the delivery of a project. Delay is the slowing down of work without stopping construction entirely and that can lead to time overrun either beyond the contract date or beyond the date that the parties have agreed upon for the delivery of the project. Delays classified into nonexcusable delays, excusable non compensable delays, excusable compensable delays and concurrent delays. Aditi Dinakar 784 Non-excusable delays are delays, which the contractor either causes or assumes the risk for. Excusable noncompensable delays are delays caused by factors that are not foreseeable, beyond the contractor s reasonable control and not attributable to the contractor s fault or negligence. Compensable excusable delays these are compensable delays are excusable delays, suspensions, or interruptions to all or part of the work caused by an act or failure to act by the owner resulting from owner s breach of an obligation, stated or implied, in the contract. Concurrent delays occur when both owner and the contractor are responsible for the delay. I.I Problem Statement Many construction projects have faced various problems and delay of time is one of the major problems. The delay in dispute settlement has manifold effects such as it will give detrimental to the relationship between owner and contractor. The contractor and the owner pay for the extra charge for the completion of the project due to delay in large construction projects. When the completion time of the construction project exceeds the agreed completion time, it is known as construction project delay. It is needed to conduct detailed investigation and identification of delay factors and then selecting the right actions to counter theses delay factors within cost and maintaining quality. The faults and errors due to the contractor cause delays and waste of capital and time The current study focuses on various factors causing the delays particularly in far off places where resources should be transported from far off places which require more time and money and where fresh work need to be done right from the excavation like removing trees and blasting few places which cannot be excavated by machinery. This study attempts to generalize. 1. To identify various causes of the delays 2. How unpredicted delays can cause delays resulting in delays of the total project 3. The effects of the delays on the project 4. Study the causes and effects of the delays at various projects and to find out the most important causes.

2 II. DELAYS There are three basic ways to categorize type of delays: Critical and noncritical Excusable and Non-excusable Compensable and non-compensable II.I Critical And Non-Critical Delays Delays that affect the project completion or in some cases a milestone date are considered as critical delays and delays that do not affect the project completion or a milestone date are considered as noncritical delays. If these activities are delayed, the project completion date or a milestone later will be delayed. The determining which activities truly control the project completion date depends on the following: 1. The project itself 2. The contractor s plan and schedule (particularly the critical path) 3. The requirement of the contract for sequence and phasing 4. The physical constraint of the project, i.e. how to build the job from a practical 5. Perspective. II.I Excusable And Non-Excusable Delays All delays are either excusable or non-excusable. An excusable delay is a delay that is due to an unforeseeable event beyond the contractor s or the subcontractor s control. Normally, based on common general provisions in public agency specifications, delays resulting from the following events would be considered excusable: 1. General labor strikes - Strikes and labor unrest are frequent causes of delay on construction projects. However, that not all strikes are considered excusable delays. Generally, a contract clause listing strikes as an excusable delay also carries a qualification that the cause for the delay must have been unforeseen and beyond the control of the contractor. Strikes that are foreseeable at the time of signing the contract are not considered excusable causes of delay. 2. Fires 3. Floods 4. Act of God - An act of God is a natural occurrence caused directly and exclusively by natural forces without any human intervention, which could not have been reasonably foreseen, nor could have been prevented. Earthquakes, landslides, tornados, hurricanes, lightning, floods, etc., are all examples of acts of God. Note, however, that mere bad weather does not qualify as an act of God. 5. Owner-directed changes 6. Errors and omissions in the plans and specifications 7. Differing site conditions or concealed conditions 8. Unusually severe weather Non-excusable delays are events that are within the contractor s control or that are foreseeable. These are some examples or non-excusable delays: 1. Late performance of sub-contractors 2. Untimely performance by suppliers 3. Faulty workmanship by the contractor or subcontractors 4. A project-specific labor strike caused by either the contractor s unwillingness to meet with labor representative or by unfair labor practice II.II Compensable And Non-Compensable Delays A compensable delay is a delay where the contractor is entitled to a time extension and to additional compensation. Relating back to the excusable and non-excusable delays, only excusable delays can be compensable. Noncompensable delays mean that although an excusable delay may have occurred, the contractor is not entitled to any added compensation resulting from the excusable delay. Thus, the question of whether a delay is compensable must be answered. Additionally, a non-excusable delay warrants neither additional compensation nor a time extension. II.III Delay Analysis Techniques Whether or not a delay is compensable depends primarily on the terms of the contract. In the most cases, a contract specifically notes the kinds of delays that are noncompensable, for which the contractor does not receive any additional money but may be allowed a time extension. Delay analysis is a analytical process that should be employed with project documentation along with collected data from project site. The selection of delay analysis depends on the variety of factors and the available records. There are five commonly used delay techniques. 1. Impacted as-planned method 2. Time impact analysis method 3. Collapsed as-built or but-for analysis method 4. Snapshot/windows/time slice analysis method 5. As-planned versus as-built windows analysis method 785

3 III. RESEARCH METHODOLOGY III.I Questionnaire Methodology The Survey is designed based to use Likert Scale on the objective of the study to find out the causes of delays in construction projects and effect of the delays on overall project. The Survey is framed in such a way that the personal view of different people involved in different projects is collected and analyzed. The questionnaire basically consists of four sections as detailed below. 1. Respondent Background - This is to collect the basic information of the respondent 2. Causes of Delays - This is used to collect the data on different causes of the delays happened in that particular project. 3. Effects of Delays - Using these questions the effects of the delays on the project are identified. 4. Measures for Minimizing Delays - The last part of the survey consists of questions regarding the methods they used to reduce the delays if any. The collected data is analyzed using Minitab software to find out the major causes of delay, the effects of the delay and how to minimize the delay of a construction project. III.III Scoring And Analysis After the questionnaire is completed, each item may be analyzed separately or in some cases item responses may be summed to create a score for a group of items. Hence, Likert scales are often called summative scales. Whether individual Likert items can be considered as interval-level data, or whether they should be treated, as ordered-categorical data is the subject of considerable disagreement in the literature, with strong convictions on what are the most applicable methods. This disagreement can be traced back, in many respects, to the extent to which Likert items are interpreted as being ordinal data. There are two primary considerations in this discussion. First, Likert scales are arbitrary. The value assigned to a Likert item has no objective numerical basis, either in terms of measure theory or scale (from which a distance metric can be determined). The value assigned to each Likert item is simply determined by the researcher designing the survey, who makes the decision based on a desired level of detail. However, by convention Likert items tend to be assigned progressive positive integer values. Likert scales typically range from 2 to 10 with 5 or 7 being the most common. Further, this progressive structure of the scale is such that each successive Likert item is treated as indicating a better response than the preceding value. (This may differ in cases where reverse ordering of the Likert Scale is needed). The second, and possibly more important point is whether the distance between each successive item category is equivalent, which is inferred traditionally. For example, in the above five-point Likert item, the inference is that the distance between category 1 and 2 is the same as between category 3 and 4. In terms of good research practice, an equidistant presentation by the researcher is important; otherwise a bias in the analysis may result. For example, a four-point Likert item with categories "Poor", "Average", "Good", and "Very Good" is unlikely to have all equidistant categories since there is only one category that can receive a below average rating. This would arguably bias any result in favor of a positive outcome. On the other hand, even if a researcher presents what he or she believes are equidistant categories, it may not be interpreted as such by the respondent. A good Likert scale, as above, will present symmetry of categories about a midpoint with clearly defined linguistic qualifiers. In such symmetric scaling, equidistant attributes will typically be more clearly observed or, at least, inferred. It is when a Likert scale is symmetric and equidistant that it will behave more like an interval-level measurement. So while a Likert scale is indeed ordinal, if well presented it may nevertheless approximate an interval-level measurement. This can be beneficial since, if it was treated just as an ordinal scale, then some valuable information could be lost if the distance between Likert items were not available for consideration. The important idea here is that the appropriate type of analysis is dependent on how the Likert scale has been presented. Notions of central tendency are often applicable at the item level - that is responses often show a quasi-normal distribution. The validity of such measures depends on the underlying interval nature of the scale. Responses to several Likert questions may be summed providing that all questions use the same Likert scale and that the scale is a defensible approximation to an interval scale, in which case the Central Limit Theorem allows treatment of the data as interval data measuring a latent variable. If the summed responses fulfill these assumptions, parametric statistical tests such as the analysis of variance can be applied. Typical cutoffs for thinking that this approximation will be acceptable is a minimum of 4 and preferably 8 items in the sum. 786

4 IV. QUESTIONNAIRE The questions about the causes for delays are divided into 7 sections containing 9 questions each. The respondent is asked to rank each of the following questions. Group-A Owner Contributed Factors 1. Delay in progress payments 2. Delay to furnish and deliver the site 3. Change orders by owner during construction 4. Late in revising and approving design documents 5. Delay in approving shop drawing and sample materials 6. Poor communication and coordination 7. Slowness in decision-making process 8. Conflicts between joint-ownership of the project 9. Suspension of work by owner Group-B Contractor Contributed Factors 1. Difficulties in financing project 2. Conflicts in sub-contractors schedule in execution of project 3. Rework due to errors during construction 4. Conflicts between contractor and other parties 5. Poor communication and coordination 6. Ineffective planning and scheduling of project 7. Improper construction methods implement 8. Delays in sub-contractors work 9. Inadequate contractor's work Group-C Consultant Contributed Factors 1. Delay in approving major changes in the scope of work 2. Poor communication and coordination 3. Inadequate experience of consultant 4. Mistakes and discrepancies in design documents 5. Delays in producing design documents 6. Unclear and inadequate details in drawings 7. Insufficient data collection and survey before design 8. Un-use of advanced engineering design software 9. Conflicts with other parties and financial problems Group-D Material Contributed Factors 1. Shortage of construction materials in market 2. Changes in material types during construction 3. Delay in material delivery 4. Damage of sorted material while they are needed urgently 5. Delay in manufacturing special building materials 6. Late procurement of materials 7. Quality problem with procured material Procuring undesired or unwanted material instead 9. Problem with material transport and processing at site Group-E Equipment Contributed Factors 1. Equipment breakdowns 2. Shortage of equipment 3. Low level of equipment-operator's skill 4. Low productivity and efficiency of equipment 5. Lack of heavy equipment when needed 6. Wrong kind or verity of equipment 7. Lack of hi-tech and advanced equipment 8. Unavailability of special equipment 9. Difficulty in transporting equipment Group-F Labor Contributed Factors 1. Shortage of labors 2. Working permit of labors 3. Low productivity level of labors 4. Personal conflicts among labors 5. High labor wages 6. Labor exodus 7. Labor strikes at site 8. Labor health problem when working in hazardous conditions 9. Labor Safety problems Group-G External Factors 1. Effects of subsurface and ground conditions factors 2. Delay in obtaining permits from municipality 3. Weather effect on construction activities 4. Traffic control and restriction at job site 5. Accident during construction 6. Changes in government regulations and laws 7. Delay in providing services from utilities 8. Delay in performing final inspection and certification 9. Civil unrest and public strikes Respondents are also asked to give their opinion on the effects of delays. 6 Questions were asked in this section. 1. Time overrun 2. Cost overrun 3. Dispute 4. Arbitration 5. Total abandonment 6. Litigation The last section includes questions about the steps that should be taken to avoid delays in construction project. 1. This section consists of 12 questions. 2. Frequent progress meeting 3. Use up-to-date technology utilization 4. Use proper and modern construction

5 5. Use appropriate construction methods 6. Effective strategic planning 7. Proper material procurement 8. Accurate initial cost estimates 9. Clear information and communication channels 10. Frequent coordination between the parties involved 11. Proper emphasis on past experience 12. Proper project planning and scheduling 13. Complete and proper design at the right time V. ANALYSIS The collected responses from different categories of people involved in construction project. The mean of each group of question is calculated using ANOVA analysis. The final result showing the contribution of different factors on the delay of a construction project is plotted on a pie chart. From the pie chart the contribution of various parties involved in the project are almost same while contractor is more slightly more for delay. VI. CONCLUSION The responses collected from the respondents make it evident that almost all parties holds nearly equal responsibility for the delays in project. The majority of people rated improper communication between the involved parties as the major problem while external reasons like lack of qualified labor, equipment and material when needed comes next in row. After analyzing the data it is clear that the contribution of Contractor in delay of the construction project is more than the client and consultant side. And the external factors contribute the least in delay of construction project. REFERENCES [1] Aibinu, A. A. and Jagboro,G.O.(2002).The Effects of Construction Delays on Project Delivery in Nigerian Construction Industry. International Journal of Project Management, Volume 20, Issue 8, November 2002, Pages [2] Arditi, D. and Pattanakitchamroon, T. (2006). Selecting a Delays Analysis Method in Resolving Construction Claims. International Journal of Project Management, Elsevier. 21 : [3] Alaghbari, W. et al. (2007). The Significant Factors Causing Delay of Building [4] Construction Project in Malaysia. [5] Chan DWM, Kumaraswamy MM. (1997). A comparative study of causes of time overruns in construction project. Hong Kong. Int J project manage. 15 (1): [6] Ahuja, H.N. Dozzi, S.P., and Abourizk, S.M. (1994). Project Management: Techniques in planning and controlling construction projects, 2nd Ed., New York. [7] Assaf, S.A., Al-Khalil, M. and Al-Hazmi, M. (1995). Causes of Delay in Large Building Construction Projects. Journal of Project Management in Engineering ASCE, 2; [8] Al-Momani, A.H. (2000).Construction delay: a quantitative analysis, Journal of Project Management 18, [9] Contracts. International Journal of Project Management, Elsevier.20:67-73 [10] Manavazhia MR, Adhikarib DK. Material and Equipment Procurement Delays in Highway Projects in Nepal. International Journal Project Management 2002; 20: [11] Theodore J. Trauner Jr. et al. (2009). Types of Construction Delays. Construction Delays (Second Edition), 2009, Pages [12] Young, J., and Jinijoo, L. (1998). Factors influencing the success of management consulting projects. International Project Management Journal 788