- Project plans
- Project activities
- Legislation and standards
- Industry context
Last edited 09 Sep 2019
Construction projects are often seen to be a balance between three related performance indicators; time, cost and quality. Generally, an increace in quality will result in an increase in cost and time, a reduction in time will result in an increase in cost and so on.
Time certainty is the likelihood that even before a project starts, but also during the project, it will be completed within the required time. Time certainty is also affected by cost certainty which is the likelihood that a project will be completed within the budgetary requirements.
Construction clients often hold these two concepts as their top priorities as delays and cost overruns can lead to higher costs for the client and a possible diminished relationship between client, contractor, occupants, customers and so on. For contractors, an excessive time extension to the project programme may mean lower than expected profits and a diminution of reputation and competitiveness.
- Clients making sudden changes and introducing variations.
- Slow decision-making.
- Unforeseen ground conditions.
- Delays in material supply.
- Inclement weather.
- Changes in market conditions.
A 1996 study by the Construction Industry Board (CIB) revealed that time certainty (and also cost certainty) is more often than not likely to be under the contractor’s control. This is mainly because time overruns are frequently seen to be:
- Symptomatic of poor management.
- The contractors’ inability to predict and control the time needed to complete a project.
- Inaccurate material estimating.
- Poor labour productivity.
- Inadequate planning.
- Poor site management.
- Increases in overheads.
- Hiring more operatives.
- Longer plant-hire periods.
- Storage of materials.
- Delayed payments from the client or penalties.
In their paper ‘Cost Certainty and Time Certainty: An International Investigation’ (Hong Xiao and David G Proverbs), time certainty was found to be largely dependent on first, cost certainty and second, the importance contractors allocate to cost, comparing them to the two sides of the same coin; neglecting one will have an adverse effect on the other. Also, the authors maintain that projects completed on time are those where the contractor realises there is no other option and so does as much as possible to bring this about.
Greater planning input by the contractor is also known to have a positive effect on improving project performance (Faniran et al., 2001) and is why faster projects are usually found to be cheaper at the tender stage, punctual to deadlines and completed to customers’ satisfaction (NEDO, 1988).
A possible indicator of a contractor’s time certainty is that delays on previous similar projects are likely to reoccur on future projects. A good reputation is therefore critical for time certainty performance.
 Related articles on Designing Buildings Wiki
- Acceleration of construction works
- Adverse weather during construction
- Certificate of non completion
- Common refusals of extensions of time
- Completion date in construction contracts
- Concurrent delay
- Contract administrator for construction contracts
- Contractor delay.
- Defects in construction
- Delays on construction projects
- Extension of time - approval letter example
- Force majeure in construction
- How to prepare a claim for an extension of time
- Liquidated damages in construction contracts
- Loss and expense
- Nominated sub-contractor
- Octoesse LLP v Trak Special Projects Ltd
- Practical completion
- Prolongation in construction contracts
- Reasonable time.
- Relevant event
- Relevant events v relevant matters
- Relevant matters in construction contracts
- Time at large
- Variations in construction contracts
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