DELAY ANALYSIS TECHNIQUES-TIME IMPACT METHOD

The fourth method of delay analysis is called time impact analysis. This method attempts to determine the impact of delay events on the contractor's intentions for the remaining works, taking into account the actual progress at the time the delay event occurred. 

The first step is to verify the contractor's planned programme and correct any errors. The second step is to identify the delay events and periods. Next, the actual progress of the works at the start of the first delay event is input into the contractor's programme to check whether the completion would have been delayed by the contractor's rate of progress. Activities representing the delay are then added to the programme, which is then re-analysed, and any further delay is recorded. It is then argued that the further delay is the contractor's entitlement to an extension of time at the time the delay event occurred. The process is then repeated for each delay event.

Time impact analysis requires a suitable  planned programme that truly reflects the contractor's intentions for executing the work. This method also requires reliable and consistent progress data at small enough intervals to make the analysis meaningful.

When undertaken properly, this method of analysis addresses the complex issue of concurrent delays, acceleration and resequencing of activities. It is often used by expert witnesses when giving opinions in arbitration or litigation. It is also the method recommended by the Society of Construction Law's Delay and Disruption Protocol.

Due to its complexity, time impact analysis has two significant disadvantages: it can be slow and so expensive to carry out; and can be difficult to communicate the approach and results.

I think that there's no single method of delay analysis that will suit all situations. The choice of method of analysis depends upon the requirements of contract, nature of delay events, quality of planned programme, records to hand, time available, value of dispute and target audience.

If there were a single method of delay analysis that yielded one result from a given set of facts then there would be little doubt as to the party responsible for the delay. Until such a method is found, however, delay analysis will continue to be a subject of much debate.  

DELAY ANALYSIS TECHNIQUES-AS BUILT BUT-FOR AND TIME -IMPACT METHOD

The third method I am going to describe is called as-build but- for and time-impact analysis. This is a more sophisticated method. In brief, as built but- for involves removing the effects of delay events from the as built programme in order to assess how the work would have progressed in absence of the delays.

First a dynamic as built programme is produced using planning software to create a model of the timing and sequence of actual events. The model must precisely replicate how the works were executed using as built start dates, finish dates and activity durations with appropriate activity logic links between activities. 

The second stage involves identifying the delay events in the as built progrsmme and apportioning them to the the party responsible for them.  The delay events are shown in the as built programme either as activities or constraints. Their impact is modeled by creating logic events between the delay events and subsequent activities.

The third stage involves removing the delays from the as built  programme to produce an as built- but programme to show how the works would have been constructed but for the delays. When used in claims for extension of time, only delays for which the contractor is not responsible are removed. It can be argued then that the extension of time due is the difference between respective completion dates of the as built programme and as built-but for the programme. In practice several iterations are needed to ensure that the model represents what would have happened but for the delays. This involves adjusting the level of detail, logic and durations of activities. 

As this method relies upon having an accurate as built programme, good as built records are essential. It is vital that the construction team is consulted in order to gain an  understanding of  the methods of construction, relationships between  activities and practical impact of delays.

This approach has a number of advantages. It is fact based and less theoretical than other methods. The basic principle is easily understood and it can be easily presented and explained. It does, however, come with a warning:care is needed to ensure that the model addresses the concurrent culpable delays, re-sequencing, redistribution of resources and acceleration. If such matters are not accounted for then the final results will be misleading. 

DELAY ANALYSIS TECHNIQUES- "IMPACTED AS-PLANNED" METHOD

Another method for assessing delays is called "impacted as-planned". This technique is the one most commonly used by contractors in claims for extensions of time. It involves inserting activities and / or constraints to represent periods of excusable delay into the contractor's planned programme. The periods of delay are logically linked to the activities in the programme to determine the impact on progress and completion. This is a prospective form of analysis as it predicts the likely impact. The argument used with this technique is that the entitlement to extension of time is the difference between the as-planned programme and the impacted as-planned programme.

The impacted as -planned technique relies upon having a good baseline programme that reflects accurately the intended method of construction. It does not require as built records but where possible it is good practice to cross check the results against as built milestones. It is the contractors' preferred method as it is relatively quick and simple to undertake, easily understood and gives results more in the contractor's favor. For very simple claims for extension of times, this approach might suffice. Where, however, the circumstances are more complex, such as where there are multiple causes of delay with a wide range of impact, this technique may fail. This is because it takes no account of the progress of the works, contractor's own delay, adjustment of resources and changes to programme logic.

This technique and the one I described in the previous article are easiest and most commonly used in claims for extensions of time. In the next article I will describe two more sophisticated methods that address many of the defects of  the "a-planned vs. as-built" and "impacted as-planned" approaches.  

   

DELAY ANALYSIS TECHNIQUES

Delay analysis is widely debated construction law subject due to number of projects not completed on time, the financial complications of late completion and often the quite different conclusions that can result depending upon the method of analysis used.

There are several methods for delay analysis which have advantages and disadvantages. Delay analysis is a technique used to identify the causes of delay and impact they have on progress and completion of a project. Without it the contractor will fail to demonstrate any entitlement to extension of time ( EOT ). 

It is crucial to any claim that the most appropriate method of delay analysis is adopted. If you choose a method that fails to deal with issues such as culpable delays, concurrent delays and changes in logic than the claim might be easily rebutted. Whereas, using a sophisticated method for a simple issue can be waste of time and money. A number of factors can influence the selection of approach-requirements of the contract, quality of contractor's planned programme, quality and extent of records and the complexity of the issue.

Methods fall into two categories: prospective or retrospective. Prospective techniques are those that predict the likely impact on the progress of the works. Retrospective techniques are those that seek to demonstrate the actual impact on the works. The latter can be used after the works have been completed or after the impact of the delay event has ceased. Prospective analysis can be used both before or after the delay effect has taken place.  

The first method is called "as planned vs. as build". This is retrospective method that involves a simple comparison of contractor's planned programme as to how it intended to execute the works with the actual events. This is done by drawing bars or lines on the planned programme that shows when the activities actually started and finished. The argument put forward when this technique is used is that the difference between the two programmes is the entitlement to extension of time.

This technique requires the contractor;s planned programme and good as built records of when the works has been undertaken. Since it is a simple graphical comparison, there's no need to have a properly logic linked programme or to use planning software. Its other advantages is that it is quick and simple to prepare and is easily understood.

The method has a number of drawbacks. It does not identify who is at fault, it does not demonstrate cause and effect, it does not take into account the contractor's culpable delays and it can only be used retrospectively. As a result, claims for extension of time based solely on this method might be not successful. Nevertheless, it is often the first step in analyzing delays as it can quickly highlight those activities that did not proceed as planned. 

In the next article I will describe  the other retrospective method called "impacted as-planned".