This International Standard specifies functional analysis and assignment procedures (FA and A, sometimes called allocation of functions) for the design of the control-room system for nuclear power plants and gives rules for developing criteria for the assignment of functions. This standard supplements IEC 60964, which applies to the design of the control-room for nuclear power plants. The purpose of this standard is to provide specific requirements for carrying out the functional analysis and assignment required in 3.1 and 3.2 of IEC 60964, and therefore supersedes the guidance given in A.3.1 and A.3.2 of IEC 60964. This standard is applicable to the design of new control-rooms or to backfits (design renewal and design modifications) to existing control-rooms. In the latter case, particular caution is to be exercised to identify areas indirectly affected as well as those directly affected.