This work discusses the problem of selecting methods for valuing the costs and estimating the time of implementing computer systems in cases when system modification is necessary. The methods presented in literature are reviewed and the stages of strategic phase of implementation characterised....

In the course of sales process of Enterprise Resource Planning (ERP) Systems, it turns out that the standard system must be extended or changed (modified) according to specific customer’s requirements. Therefore, suppliers face the problem of determining the cost of additional works. Most...