COSYSMO supports the ANSI/EIA 632 standard as a guide for identifying the Systems Engineering tasks and ISO/IEC 15288 standard for identifying system life cycle phases. Several CSSE Affiliates, LAI Consortium Members, and members of the International Council on Systems Engineering (INCOSE) have been involved in the definition of the drivers, formulation of rating scales, data collection, and strategic direction of the model.
Similar to its predecessor COCOMO, COSYSMO computes effort (and cost) as a function of system functional size and adjusts it based on a number of environmental factors related to systems engineering.COSYSMO's central cost estimating relationship, or CER is of the form:
where "Size" is one of four size additive size drivers, and EM represents one of fourteen multiplicative effort multipliers.