For the ECC form the parties are the Client and Contractor with administrative roles for the Project Manager and Supervisor. Further named roles are; Others, Subcontractor, Senior Representative, Adjudicator and Tribunal. Optional clauses also provide for Information Provider (X10) Promoter, Partners, Core Group (X12) Supplier, Named Supplier (Y(UK)1) beneficiary (Y(UK)3).
The responsibilities for each are reasonably extensive with the Contractor having the most actions and obligations under the contract, followed by the Project Manager.
Essentially the Client facilitates the construction and pays for the work, the Contractor undertakes the works, the Project Manager administers the contract (on behalf of the Client) and the Supervisor assumes responsibility for quality control issues.
Some of the actions have changed between NEC3 and NEC4,, with the introduction of new requirements or procedures and revision to existing procedures, although the basic principles remain the same. The Employer under NEC3 is now called the Client ,