Getting the Measure of Disruption | Disruption vs Delay

Part One

By Stephen Fitzgerald

Construction projects often result in cost overruns because of disruptions and delays created by the employer or contractor. This series of articles discusses aspects of disruption and identifies issues related to measuring disruption on Construction projects. The first article in the series identifies what disruption is and what is to be measured.

Introduction

 Delay and disruption are often (incorrectly) referred to by industry practitioners as if they are one and the same. Although the terms “delay” and “disruption” are commonly used interchangeably, they are entirely separate issues that need to be addressed and measured separately. This article will review the relationship between delay and disruption and review the measurement of disruption, as distinct from delay.

 What Is Disruption (As Distinct from Delay), and What Is to Be Measured?

 Definitions

Disruptions prevent the contractor from completing work activities within its originally planned costs,[1] whereas delays prevent the contractor from completing the works within the originally planned duration. Delay claims capture the additional time (and associated time-related cost) due to the reduced rate of progress, whereas disruption claims capture the additional cost of completing the work activities.

Disruption is not delay; however, there may be a relationship between disruption and delay in that a contract that has been delayed will most likely have been disrupted, and both may have arisen from the same events. Further, delay and disruption can be interrelated, where disruption can contribute to causing delay or delay can cause disruption. In these circumstances, the Society of Construction Law (SCL) suggests that a contractor may undertake a delay analysis to support its claim for disruption.[2]

It should be noted that delays are generally measured by way of a programme analysis that focuses on critical path activities. However, a critical path analysis is unlikely to provide the basis for a realistic assessment of disruption because, typically, only 20 per cent of programme activities are on the critical path, whereas disruption can affect 100 per cent of programme activities.

Therefore, due to the differing components of disruption (cost) and delay (time) the effects should be analysed independently and rely on different analysis methods.

Disruption can be described as the disturbance to the regular and economic progress of the works,[3] which results in additional cost where labour or plant is underutilised.[4] This disturbance, or hindrance, interrupts the contractor’s normal working methods, resulting in lower efficiency.[5] Therefore, disruption is fundamentally about reduced productivity in the execution of work activities.[6]

 Production & Productivity

 When analysing disruption, it is important to distinguish “production” and “productivity.” Production is measured in units of work output (e.g., m2 m3 etc.) while productivity is usually measured as the units of production per unit of effort. It can be expressed as output divided by input (m2/man-hour) and alternatively, it can be expressed as input divided by output (man-hour/m2).

Productivity loss happens when a contractor is not accomplishing its anticipated planned rate of production,[7] where the contractor produces less than its planned unit of output per planned unit of input. Disruption is the measure of the loss of productivity between the contractor’s planned and actual rates of production.[8]

So, measurement of disruption equates to measuring productivity loss. Organisations like the Society of Construction Law (SCL) and the Association for the Advancement of Cost Engineering International (AACEI) recommend techniques to measure disruption which will be discussed further in the next article of this series.

 References

1. Thornton, P & Attia, F point out in their article Productivity-based disruption claims in the Middle East (Const. L. J. Volume 12 Issue 2 June 2017) that an academic study by Semple et al (1994) found that disruption claims constituted half of all claims submitted. King, C. backs this view in an article (2017) Disrupted? Prove it! (Fenwick Elliot Insight Issue 70), stating that in many instances it is disruption more than delay which causes the losses suffered by contractors. Burr. A & Tyerman. D (2017) also have the same view in; The analysis of programme disruption: a pragmatic approach (Const. L.J. 2017, 33(2), 92-101) saying that disruption, as distinct from delay, has a disproportionate effect on project performance and outcome.
2. Burr, A. & Tyerman, D. (2017) The analysis of programme disruption: a pragmatic approach Const. L.J. 2017, 33(2), 92-101
3. Colin, E. Howick, S Issues in establishing blame in disrupted projects Const. L. J. 2020, 36(2), 103-117
4. Society of Construction Law Delay and Disruption Protocol (2nd edn), Society of Construction Law (UK), Para 18.29 SCL second edition
5. Ramsay, V. Furst, S. (2016) Keating on Construction Contracts, 10th edition. London, Sweet & Maxwell (para. 8-064).
6. Dennys, N. and Clay, R. (2020) Hudson’s Building and Engineering Contracts Atkin Chambers 14th edition, Thomson Reuters
7. Gibson, R. (2015) Practical Guide to Disruption and Productivity Loss on Construction and Engineering Projects, 1st Edition John Wiley & Sons (page.108)
8. Ibid (page. 110)
9. Ibid (page 123)
10. Keane P J, Caletka A F, (2015) Delay Analysis in Construction Contracts 2nd Edition, Chichester, Wiley Blackwell (page 94)