Both PERT and CPM are network analysis techniques. But CPM was developed independently of PERT and is widely used in the construction industry. CPM may be thought of as a subset of PERT. Like PERT, it is a network technique, but, unlike PERT, it uses deterministic time and cost estimates. Its advantages include cost estimates plus the concept of "crash" efforts and costs. Activity times are estimated for normal effort and crash effort. Crash time is the time to complete an activity assuming that all available resources were devoted to the task overtime, extra crew, etc.). Activity costs are also estimated for normal and crash efforts. These estimates allow the project manager to estimate the costs of completing the project if some of the activities are completed on a crash basis. The network diagram is constructed in the same manner as PERT diagrams. Once the diagram is constructed, the critical paths are found for normal and crash times. More than one critical path may exist for each diagram.

An EDI application should meet business objectives and satisfy user and control requirements. The internal auditors should consider the organization's important EDI applications because they represent significant risk exposures and control problems. This role is within the scope of work of the internal auditors, who are charged with examining and evaluating internal control and the quality of performance in carrying out assigned responsibilities.

Time series data pertain to a given entity over a number of prior time periods. Cross-sectional data, however, pertain to different entities for a given time period or at a given time. Thus, cross-sectional regression analysis is the most appropriate statistical tool because it compares attributes of all stores' operating statistics at one moment in time.