Innovation: Early warning of computer fiasco: Simulating techniques can now prevent expensive mistakes in the development of sophisticated software systems

SIMULATIONS can now show exactly how a complex computer system will work before any money is spent on development or installation. Rapid increases in computer power have made it possible to simulate finished products on a computer screen before the first component is ordered from a supplier.

This ability is already applied to check designs of products ranging in sophistication from Rolls-Royce aero-engines, to fitted kitchens sold by British Gas. Now computer simulation is being turned on computer systems themselves.

The developer of the new technique, ERA Technology, says this would help avoid tragic failures like the London Ambulance Service computerised call handling system, or the huge embarrassment and waste of money of the Stock Exchange's aborted share-dealing system.

In a recent survey by Price Waterhouse of senior executives with responsibility for computer systems in the financial sector, 25 per cent of respondents said that more than half of all projects fail. Many that work cost more to implement than proposed at the outset, or do not do what they were supposed to.

'The principle of computer simulation is now accepted practice in more mature areas of science and technology, including the design of aircraft, bridges and motorcars,' said Kevin Dawson, at ERA Technology. 'Until now, though, such methods have not generally been used in the effective design of information technology systems, where they may perform an even more vital role.'

One reason is that computer systems are more dynamic than other products. The challenge has been to simulate accurately the huge number of events that occur within a system. 'There are many unknowns. For example, in a distributed database different people can put in data at different times,' Mr Dawson said.

ERA Technology has spent eight years developing its simulation technique. Its first big test will be in the procurement of a computer system by the Home Office, where the technique is being used to assess the proposals of companies bidding against the published requirement. Although in this case ERA will act as a consultant, the organisation will also sell the software to companies that want to do their own simulations.

The elements of a system such as communications networks, computers, operating systems and applications software, are simulated separately, and can then be plugged together to create a complete simulation. 'This can be used to help define the specification of a system and evaluate proposed solutions,' Mr Dawson said.

The complexity of the simulation can vary depending on the client's needs, but it is possible to examine aspects ranging from human factors, such as how long it will take staff to input the required data and how many mistakes they are likely to make, to technical issues such as how a single byte of data will move around the system. The simulation technique not only analyses how a proposed system will perform, it also simulates the environment in which it will operate. This means the system can be tested against the business requirement before any money is spent on its development or installation.

The technique complements existing methods of testing computer systems such as prototyping. But Mr Dawson points out that prototyping involves actually buying a computer and writing some software.

'Until the development of ERA's simulation technique, no effective solution has been proposed to deal with the dynamic problems which can plague information technology systems and can often result in poor system response time, incorrect information flow and bottlenecks,' he said.