ISO 19901-5:2003 specifies requirements for controlling the weight and centre of gravity (CoG) by means of mass management during the engineering and construction of structures for the offshore environment. The provisions are applicable to offshore projects that include structures of all types and materials.

ISO 19901-5:2003 differentiates between projects where considerations with regard to weight and CoG have a high priority as a result of weight and/or CoG sensitivity, and projects where weight and CoG are of little consequence. This differentiation has been made by the introduction of three different classes of structure (Class A, Class B and Class C). Depending on the degree of control necessary, different clauses of ISO 19901 will apply; clause 4 provides guidelines for assigning one of these classes.

ISO 19901-5:2003 specifies quality requirements for reporting of weights and centres of gravity, specifies requirements for weight reporting, provides a basis for overall project status reports or management reports for all classes, specifies requirements for weight and load budgets for offshore installations, specifies the methods and requirements for the weighing of major assemblies and the determination of weight and centre of gravity, specifies requirements for weight information from suppliers, including weighing of equipment and bulk materials for offshore installations.

It may be used as a basis for planning and presentation of the contractor's weight-reporting system; as a basis for evaluation of the contractor's weight-reporting system; as a means of refining the structural analysis/model; as a contract reference between the ordering client and the contractor; and as a basis for costing.