Being armed to the teeth with a fancy computer program is all very well but, as a recent case illustrates, what matters is the quality of the data fed into it

One of the biggest problems when dealing with disputes – indeed the quicksand into which many an otherwise respectable claim sinks without trace – is proving what is commonly known as cause and effect. This quicksand is particularly perilous in disputes involving responsibility for delay and the entitlement to extensions of time for completion.

How such matters were approached in the days before computer software became a standard part of the armoury of programme and planning consultants is not something that even I am old enough to comment upon. But I do recall my excitement when I felt I had at last mastered the concept of critical path methodology. At last, I had the means to solve those really thorny problems and, since it was based on scientific analysis, there was surely little anyone could do to cast doubt upon it. Planning and programme experts, now armed to the teeth with Primavera, Project or other such software, have become central players in this type of dispute resolution, with their science fiction-like ability to produce answers at the push of a button.

However, the fact that the process involved the application of science may well have been falsely reassuring. Indeed, I must confess to being somewhat nonplussed when, time and again, two experts given the same set of facts come up with alarmingly different answers. I therefore welcomed the Society of Construction Law’s initiative to prepare a protocol to harmonise, as far as possible, both the principle and practice of this form of delay analysis.

The million dollar question was, of course, what the courts would make of all this. Indeed, one of the most surprising aspects of Judge Wilcox’s recent decision in Skanska vs Egger was just how little guidance the courts have given in the past on the proper role of software in this context.

One of the issues in that case was the extent to which delay in completion of various works was attributable to the performance of subcontractors or alternatively to the late issue of information by the client’s design team.

On that issue, Skanska relied upon the evidence of a planning consultant involved during the project. Judge Wilcox described this witness as “objective” and “meticulous about detail”. The judge was particularly impressed by the accessibility of his evidence.

Egger's witness had spent as much as 75% of his time acting as a professional expert rather than a practitioner

However, he was unimpressed by some rather below-the-belt criticism from the expert engaged by the other side concerning the inferiority of the Skanska expert’s software. Indeed, the judge particularly valued the fact that he was “not hidebound by theory when demonstrable fact collided with computer program logic”.

In contrast, the judge appeared unhappy that, in recent times, Egger’s witness had spent as much as 75% of his time acting as a professional expert rather than as a programme consultant. He was even more unhappy that, far from being personally involved in the selection of the data himself, this process had been carried out by a team of assistants and the work product had not been checked by the expert. Perhaps inevitably, upon cross-examination, the expert proved not entirely familiar with the detail of his own report.

The judge stressed that a computer system of this sort depended entirely on the quality of the information that was fed into it. In this case the judge was satisfied that the program used by Egger’s expert for these purposes had become largely irrelevant.

This decision will make salutary and necessary reading for those undertaking the onerous but privileged role of expert witness. It represents a strong reminder that, although a useful tool for use in the delay analysis process, a computer program is really only a glorified calculator and is certainly no substitute for the direct application of professional experience and objective judgement based upon clear knowledge and understanding of the actual facts. I think we will be seeing a lot of practitioners tugging hard on their socks, and that is probably no bad thing.

Dominic Helps is a partner with solicitors Shadbolt & Co