This appeal is against the judgment of the Gauteng Division of the High Court, Pretoria (the high court), which set aside certain procurement contracts entered into between the appellant, Siyangena Technologies (Pty) Ltd (Siyangena) and the first respondent, the Passenger Rail Agency of South Africa (PRASA). Siyangena was appointed by PRASA to supply and maintain an integrated security access management system (ISAMS) at various train stations. The equipment – which included public address facilities, speed gates and electronic display boards – was intended to enhance the safety, access and efficiency of the public rail commuter system, which PRASA is under a statutory duty to provide and maintain.
 The high court found that in contracting for these goods and services with Siyangena, PRASA, as an organ of state, failed to act in a manner that is ‘fair, equitable, transparent, competitive and cost effective’ in accordance with the provisions of s 217 of the Constitution. The high court declared the award of the contracts to the value of approximately R5.5 billion invalid, and set them aside in terms of s 172(1)(a) of the Constitution. The high court further directed, as part of its remedial powers in terms of s 172(1)(b) of the Constitution, that an independent engineer be appointed in order to determine whether any of the payments made to Siyangena by PRASA should be set off against the value of the works done. It is principally this latter conclusion that occupies our attention in this appeal, which is with the leave of the court below.