In addition, SAM software must cater for myriad different licence terms, ranging from those related to named users to licences that apply to each CPU. The recent development of servers with multiple cores has posed problems for software suppliers accustomed to charging customers a fee for each server an application is installed on. Software companies have still not settled on a good solution, analysts say.

The industry itself has been keen to maximise revenues from licences. So-called true-ups -- reports on the size of a user's estate which are used to calculate licence fees -- can account for up to 15 per cent of revenues, say industry insiders. "It's easy pickings to go after your customers: all big suppliers have licence-management practices," says Patrick Gunn, a vice president of .

But suppliers are taking steps to make it easier for customers to manage their licences and software companies have collaborated on creating a series of ISO standards governing several aspects of SAM.

The latest concerns tagging -- the headers that identify a piece of software -- and seeks to lay down a standard way of identifying software from different suppliers. In addition, the IT Infrastructure Library (Itil), a widely used methodology for managing IT, has been extended to include SAM. "The ISO 19770 standard is only just coming out, but we anticipate it will be widely used," says Tony Baron, global vice president of IT services firm Dimension Data, and one of the authors of Itil.

In addition, industry body the Business Software Alliance (BSA) has just launched a programme designed to help businesses implement SAM programmes. The aims to provide its members and their partners with a set of online SAM tools and training frameworks.