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Excusable Events
Variation / Change Order: If a variation instructed by the Employer affects the Time for Completion, it gives rise to entitlement to an Extension of Time (EOT); cost entitlement is assessed under Clause 13.
Engineer’s Instruction: Instructions affecting the execution of the Works that cause delay may entitle the Contractor to an EOT.
Late Site Possession: Failure to give possession of the Site on time entitles the Contractor to EOT and generally to cost.
Suspension by Engineer / Employer: Suspension of the Works entitles the Contractor to EOT and, subject to conditions, to cost.
Delayed Drawings or Instructions: Late issuance of necessary drawings or instructions affecting the critical path gives rise to EOT.
Employer’s Site Data Risk: Errors or inadequacies in Site Data provided by the Employer may entitle the Contractor to both time and cost.
Delayed Payment: Late payment entitles the Contractor to financing charges; it is not, in itself, an automatic ground for EOT.
Delay in Permits by Employer: Delays in permits for which the Employer is responsible give rise to EOT.
Free-Issue Materials Unavailable: Failure by the Employer to provide free-issue materials entitles the Contractor to EOT.
Error in Setting Out Employer-related setting out errors not reasonably detectable by an experienced contractor give rise to EOT.
Inspection Delay: Delays in inspection or approval processes affecting the critical path entitle the Contractor to EOT.
Delay Due to Other Contractors: Delays caused by other contractors under the Employer’s coordination responsibility may entitle the Contractor to EOT.
Testing Delay: Employer-related delays in testing procedures give rise to EOT.
Taking Over Delay: Delays in Taking Over procedures affecting completion entitle the Contractor to EOT.
Excusable but Non-Compensable Events
Exceptional Adverse Climatic Conditions: Exceptional weather conditions entitle the Contractor to EOT; cost is generally not recoverable.
Force Majeure: In cases of Force Majeure, EOT is granted; cost is recoverable only under the conditions set out in Clause 19.4.
Labour Strikes: General strikes beyond the Contractor’s control may entitle the Contractor to EOT; cost entitlement depends on the circumstances.
Risk Allocation Dependent Events
Unforeseeable Physical Conditions: Unforeseeable physical conditions entitle the Contractor to both EOT and cost.
Fossils / Antiquities: Discovery of fossils or antiquities may entitle the Contractor to EOT and cost.
Delays by Authorities: Delays caused by public authorities entitle the Contractor to EOT; cost entitlement depends on contractual risk allocation.
Common delay analysis methods, classified according to their analytical characteristics, are presented in Table 1 below.
Considering the factual circumstances that arise during the execution of projects, Windows Analysis, which retrospectively calculates and apportions delays, is one of the most frequently preferred delay analysis methods in practice [1–4].
Table 2 below illustrates the programme documentation and record-keeping requirements of the aforementioned delay analysis methods.
What is Window Delay Analysis? How is it Performed?
Window Delay Analysis is a retrospective delay analysis method in which delays are examined by dividing the project duration into specific time intervals (windows). It is particularly used in large and complex projects to determine in which period a delay occurred and which party bears the associated risk.
This method is based not on theoretical assumptions but on actual progress data and updated programmes. For this reason, it is regarded in both academic literature and practice as one of the most reliable analytical delay analysis methods (SCL Delay and Disruption Protocol, 2nd Edition).
Fundamental Principle of Window Analysis
The core principle of Window Analysis is as follows:
The project duration is divided into defined time periods, and the evolution of the critical path is analysed within each period.
Each window is typically established based on:
Monthly programme updates,
A significant project event date, or
A contractual reporting period.
How is it Performed?
1. Identification of Window Periods: The project timeline is divided chronologically (for example, by monthly updates).
2. Establishment of the Starting Point: Each window begins with the accepted version of the most recent updated programme.
3. Examination of the Critical Path: Delay events occurring within the relevant window are analysed according to their impact on the critical path.
4. Calculation of Net Delay: At the end of each window, the shift in the project completion date is calculated.
5. Apportionment of Delay: Delays occurring within the relevant window are categorised as:
. Employer risk,
. Contractor risk, or
. Neutral risk.
This process is repeated for all windows, and the total net delay is determined.
Advantages
Based on actual progress
Dynamically captures changes in the critical path
Suitable for concurrency analysis
Widely accepted in courts and arbitration proceedings
Limitations
Requires extensive programme documentation
Updated programmes must be available in native format
Requires technical expertise
Academic Evaluation
Within the context of retrospective delay analysis, Window Analysis is one of the most robust methods for demonstrating causation. However, reliable results can only be achieved if regular programme updates and contemporaneous records are available.
1. Purpose of the Protocol
To promote consistency and good practice standards in delay and disruption analysis in construction projects.
To support proactive project management and the analysis of events at the time they occur (contemporaneous analysis), with the aim of preventing disputes.
To provide structured guidance for Extension of Time (EOT) and disruption claims.
Important Note: The Protocol is not a contractual document; it should always be remembered that express contractual provisions and applicable laws prevail over the Protocol.
2. Programme and Record Management Principles
“No records, no claim.”
Records form the foundation of all analyses and should be maintained contemporaneously with the events.
An approved baseline programme should be established at the outset of the project and updated regularly throughout the project duration.
Programmes should be shared not only in PDF format but also in their native software format.
Unless otherwise stated in the contract, float is not owned exclusively by either the Employer or the Contractor; it is considered a shared project resource.
3. Extension of Time (EOT) Management
Avoiding the “Wait and See” Approach:
EOT applications should be assessed at the time the delaying event occurs or as soon as reasonably possible thereafter.
Critical Path Analysis:
Only events that affect the project completion date or contractual milestones (i.e., events impacting the critical path) give rise to entitlement to an EOT.
Note: Entitlement to an EOT does not automatically give rise to entitlement to financial compensation; these are separate considerations.
4. Concurrent Delay
Concurrent delay occurs where an Employer risk event and a Contractor risk event take place during the same period, and both impact the critical path, thereby delaying completion.
SCL Principle:
In cases of true concurrency, the Contractor is generally entitled to an Extension of Time (thus avoiding liquidated damages), but is typically not entitled to additional financial compensation for that period.
5. Disruption
Disruption refers to loss of productivity resulting from interference with the Contractor’s normal working methods, even where the overall completion date is not affected.
The Protocol’s preferred method for measuring disruption is the Measured Mile analysis, which compares an affected period of work with an unaffected (clean) period.
6. Recommended Delay Analysis Methodologies
The Protocol recommends six principal methods depending on the project circumstances and available data:
Impacted As-Planned Analysis: Adding delay events to the baseline programme (prospective method).
Time Impact Analysis (TIA): Incorporating delay events into the updated programme (contemporaneous / preferred method).
Time Slice Windows Analysis: Examining the project in periodic windows (retrospective method).
As-Planned vs As-Built Windows Analysis: One of the most commonly used retrospective methods.
Retrospective Longest Path Analysis: Tracing the critical path backwards from the completion date.
Collapsed As-Built Analysis: Removing delay events from the as-built programme to assess their impact.
7. Critical Success Factors
Avoidance of Global Claims: The cause-and-effect relationship (causation) between each event and its impact must be demonstrated separately for each delay event.
Mitigation: The Contractor is obliged to take reasonable steps to mitigate the effects of delay when such events occur.
Prolongation Claims
Evaluation of extended site costs arising from excusable delays, including labour, plant, equipment, and site overheads.
Disruption Claims
Quantification of reduced productivity impacts through the Measured Mile method or other widely accepted methodologies.
Recovery of Head Office Overhead – HOOH
Application of industry-standard formulae such as Hudson, Emden, or Eichleay for the recovery of unabsorbed head office overhead.
Acceleration Claims
Calculation of additional resources, overtime, and related costs incurred as part of mitigation or acceleration measures.
Interest Claims
Assessment of financial losses resulting from late payments or under-certified interim payments.
Finance Charges
Quantification of increased borrowing or financing costs arising from withheld or delayed entitlements.
Price Escalation Claims
Analysis of cost increases in materials, fuel, and labour due to inflation or market volatility.
Loss of Profit Claims
Estimation of foregone profit resulting from wrongful termination, reduction of scope, or unjustified delay.