Different Delay Analysis Techniques
- Marty Fuentes
- | December 14, 2022
Construction projects experience delays almost all the time for various reasons. Causes could be traced to that instigated by the owner, contractor, neither or both. Delays are costly and time consuming. The procedure of analyzing what causes such, by whom and up to what extent entails additional financial burden to the parties involved. A number of claims analysis techniques have been introduced with varying degree of results accuracy and some often offer favorable outcome to the claims proponent, consequently, arising the difficulty for both sides to reach an agreement. The Time Impact Analysis (TIA) has been recognized by practitioners and researchers to produce the most reliable and unbiased results. The drawbacks of this method, however, are its complexity to perform and the stringent requisite of having well-maintained and relevant project documentations.
Project Delays
Construction delays have been a common phenomenon in projects (Alkass et al. 1995; Arditi & Pattanakitchamroon 2006; Braimah 2013; Zaneldin 2006). A project is considered delay when the contractor fails to deliver it within the stipulated or agreed completion date. Completing on time poses challenges to contractors due to the complexity, unpredictability and the multifaceted nature of engineering and construction projects (Kartam 1999).
Delays mean loss of potential revenue to the owner should the project been completed as scheduled while on the side of the contractor, possible over-spending on the project due to additional costs brought about by the extended execution period. They are considered as the most common and most expensive sources of disputes in construction projects (Kumaraswamy & Yogeswaran 2003). They can be attributed as caused by the owner, by the contractor, neither or both. A number of research have been made in an effort to identify causes of delays and in the process, categorize them mainly by the faulting entities (Kumaraswamy & Yogeswaran 2003). The type of contract also provides the sound basis in allocating the risks associated with schedule overruns to the parties involved (Ahmed et al. 2002).
Contracting sides are well aware of the exorbitant expenses linked to delay claims especially if the issue reaches the litigation stage (Kartam 1999). Various factors can influence a project to miss the agreed construction deadline, hence, the essentiality to precisely identify the causes, types and the culpable bodies. Aside from identifying what prompted the delays and by whom, there is also an imperative need to identify the techniques available in assessing claims and their resulting degree of accuracy. Different methods are used in practice with varying extent of accuracy and complexity to perform (Gothand 2003). However, there is no single tool universally accepted in the industry. As unique each project is, the applicable method largely depends on available project information, scheduling software in use and the amount of effort and cost willingly to be put up for the analysis (Arditi & Pattanakitchamroon 2006). It must be pointed out, however, that of all the available tools for claims analysis, researchers and field practitioners alike agree that the intricate critical path method-based Time Impact Analysis provides the relatively most credible results.
Delay Causes
In the study conducted by Assaf & Al-Hejji (2006) for large construction projects they have surveyed in Saudi Arabia, it was found that about 70% suffered delays. Among the main reasons for the delay are related to the approval of shop drawings by the owner, changes in design, subcontractors’ schedule issues, late payment to contractors, resource inadequacy and sluggish decision making by the owner’s management. Al-Momani (2000) examined records of 130 public building projects in Jordan and discovered that almost 82% of the projects did not meet the target completion date. It was found that the weather inclement, site conditions, changes in design and quantity, and late material deliveries were among the major causes of delay. Similarly, the 28 road and 164 building projects in Jordan evaluated by Battaineh (1999) indicated about 20% and 60% schedule overruns with respect to the planned duration, respectively. Zaneldin (2006) delved into the 124 claims related to various construction projects mainly in buildings, roads and infrastructures, and airports in Abu Dhabi and Dubai in the UAE within the inclusive period between 2000 and 2004 and concluded that change orders and delays caused by the owner were among the top ranked causes of claims. Suspension of work, accidents and errors in planning were placed at the bottom 3 of the 26 identified causes of claims. Ogunlana, Promkuntong & Jearkjirm (1996) inferred that building projects in developing countries such as Thailand encountered problems in insufficiency of supply of resources, incompetency of contractors and problems brought about by clients and consultants. In Nigeria, causes of delay were identified by Mansfield, Ugwu & Doran (1994) as due to incompetency in contract management, poor planning, delay in payment for completed works, varying site conditions and materials supply shortage. Kumaraswamy & Yogeswaran (2003) investigated 67 engineering projects in Hong Kong and found that 85% encountered delays. The precursory literatures manifest the widespread occurrence of delays in the construction industry. A number of reasons have been cited causing extended construction period such as due to the owner initiated change orders, poor productivity by the contractor, unfavorable weather and others. Different geographic location and economic condition dictate the contributory level of these delay factors.
Types of Delays
Delays can be caused by the contractor, owner or by a third party. Non-excusable delays (NED) are contractor-caused such as due to inefficient work production. Normally, the contractor has the obligation to pay the owner liquidated damages but this depends on the contract condition. Excusable compensable delays (ECD) are caused by the owner: for example, an instruction initiated by the owner to change some aspect of the work wherein, depending on the magnitude and the effect on the schedule, the contractor is entitled to a paid extension of time. When the delay is caused by a third party, classified under the excusable non-compensable delays (ENCD), neither the contractor nor the owner is deemed to be at fault. Such case holds true when the project experiences extreme bad weather restricting progress at site. In such situation, the contractor is accorded additional time equitable to the delay incurred due to that caused by the weather disturbance but without additional payment from the owner (Kartam 1999). Classification of delays is important in identifying the responsible parties and is vital in the time and cost impact analysis during the substantiation of delay claims.
Schedule-based Delay analysis Techniques
Various delay analysis techniques are used in the construction arena. The most commonly used, in the order of increasing accuracy and intricacy, are: (1) Global impact; (2) Net impact; (3) Impacted as-planned; (4) Collapsing as-built; (5) Window analysis; and, (6) Time impact analysis (Alkass et al. 1995; Arditi & Pattanakitchamroon 2006).
In the global impact technique, delays caused by the owner are simply added-up together and assumed the each impacts the overall completion date. In other words, delays are over-estimated in favor of the contractor.
The net impact tool is performed by comparing the as-planned and the as-built schedules. These two schedules, therefore, are needed to be available in order to proceed with this technique. Overall project delay is calculated from the difference in the finish dates of the two mentioned schedules. The identification of the responsible parties and the apportioning of the delays are ensued. The technique offers a straightforward analysis approach, however, it does lack the accuracy by not considering the dynamic nature of the critical path (Arditi & Pattanakitchamroon 2006). The critical path dictates the overall project duration and it continuously changes per the progress of interconnected activities in the course of the construction (Gothand 2003). The critical path method (CPM) has become the widely used approach in the analysis of delays and in resolving claims disputes (Householder & Rutland 1990; Ibbs & Nguyen 2007).
One of the CPM-based techniques is the impacted as-planned. Delays caused by the owner are introduced into the approved baseline or as-planned schedule and the overall duration delay is determined by the shift in the completion date. It is easy to undertake needing only the as-planned schedule. However, the apparent deficiency of this method is the sole reliance to the as-planned schedule and in assuming that the execution of the project was implemented in accordance with the preconceived schedule. Moreover, as with the earlier method, the technique does not take into account the movement of the critical path as the project progresses, changes in the work sequence and actual duration to complete the activities (Arditi & Pattanakitchamroon 2006).
The collapsing as-built method addresses the shortcoming of the impacted as-planned by taking into consideration the actual events that have transpired in the execution of the project. This is the rightful technique to utilize when the available schedule is only the as-built. As simple as the technique is, however, it does not cover the periodic changes of the critical path for the precise responsibility allocation of delays.
In the window analysis and the time impact analysis (TIA) techniques, delays are immediately reflected into the working schedule. Activity relationships are adjusted accordingly to reflect actual work sequence at site. The dynamism of the critical part is considered with the periodic updating of the working schedule. The techniques provide the most accurate results in comparison to the other methods discussed. However, with the high level of accuracy comes as well the meticulous requirement of having regularly updated working schedules available or at least possible to produce from the project database (Arditi & Pattanakitchamroon 2006). Window analysis is distinguished from the TIA in that the former is used after the project has been completed while the latter is applicable for forward-looking assessment or while the project is still on-going (Arditi & Pattanakitchamroon 2006; Braimah 2013; Gothand 2003; Hegazy & Zhang 2005). The strict prerequisite requirements make practitioners apprehensive of using these techniques. Nonetheless, if performed properly, they offer a high degree of reliability that both the owner and the contractor could certainly benefit from.
The Bottom Line
- Different methods are used in practice with varying extent of accuracy and complexity to perform in delay analysis.
- There is no single tool universally accepted in the industry.
- As unique as each project is, the applicable method largely depends on available project information, scheduling software in use and the amount of effort and cost willingly to be put up for the analysis.
- It must be pointed out, however, that of all the available tools for claims analysis, researchers and field practitioners alike agree that the intricate critical path method-based Time Impact Analysis provides the relatively most credible results.
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References
Ahmed, S.M., Azhar, S., Castillo, M. & Kappagantula, P. 2002, ‘Construction delays in Florida: An empirical study’, Final report. Department of Community Affairs, Florida, US.
Al-Momani, A.H. 2000, ‘Construction delay: a quantitative analysis’, International journal of project management, vol. 18, no. 1, pp. 51-9.
Alkass, S., Mazerolle, M., Tribaldos, E. & Harris, F. 1995, ‘Computer aided construction delay analysis and claims preparation’, Construction Management and Economics, vol. 13, no. 4, pp. 335-52.
Arditi, D. & Pattanakitchamroon, T. 2006, ‘Selecting a delay analysis method in resolving construction claims’, International Journal of project management, vol. 24, no. 2, pp. 145-55.
Assaf, S.A. & Al-Hejji, S. 2006, ‘Causes of delay in large construction projects’, International journal of project management, vol. 24, no. 4, pp. 349-57.
Battaineh, H.T. 1999, ‘Information system of progress evaluation of public projects in Jordan’, MSc thesis, Dept. of Civil Engineering, Jordan Univ. of Science and Technology, Irbid, Jordan.
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Householder, J.L. & Rutland, H.E. 1990, ‘Who owns float?’, Journal of Construction Engineering and Management, vol. 116, no. 1, pp. 130-3.
Ibbs, W. & Nguyen, L.D. 2007, ‘Schedule analysis under the effect of resource allocation’, Journal of construction engineering and management, vol. 133, no. 2, pp. 131-8.
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Mansfield, N.R., Ugwu, O. & Doran, T. 1994, ‘Causes of delay and cost overruns in Nigerian construction projects’, International journal of project Management, vol. 12, no. 4, pp. 254-60.
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Zaneldin, E.K. 2006, ‘Construction claims in United Arab Emirates: Types, causes, and frequency’, International Journal of Project Management, vol. 24, no. 5, pp. 453-9.