A tender is a submission made by a prospective supplier in response to an invitation to tender. It makes an offer for the supply of goods or services. Tender documents are prepared to seek tenders (offers).
Generally, tendering refers to the suppliers required to complete construction works, rather than the process of selecting consultancy services which is commonly referred to as appointment.
Tender documents may be prepared for a range of contracts, such as equipment supply, the main construction contract (including design by the contractor), demolition, enabling works, etc.
Ideally, tender documents should be broken down into a series of packages (even if there will only be one main contract) each with its own design drawings and specifications suitable to be issued by the main contractor to potential sub-contractors. This makes the tender easier for the contractor to price and easier for the client to compare with other tenderers.
It is important, when this is done, to ensure that the interfaces between packages are properly identified and clearly allocated to one package or another. Having too many packages increases the number of interfaces and so the potential problems. The cost plan (pre-tender estimate) should also be re-assembled package by package to allow easy appraisal of tenders received.