You have just performed a cpm analysis and have found that more than one path through the project network has zero slack values. What can you conclude?

There are multiple critical paths

Explanation:

The critical path method (CPM), or critical path analysis (CPA), is an algorithm for scheduling a set of project activities. It is commonly used in conjunction with the program evaluation and review technique (PERT). A critical path is determined by identifying the longest stretch of dependent activities and measuring the time required to complete them from start to finish.

The essential technique for using CPM is to construct a model of the project that includes the following:

Using these values, CPM calculates the longest path of planned activities to logical end points or to the end of the project, and the earliest and latest that each activity can start and finish without making the project longer. This process determines which activities are "critical" (i.e., on the longest path) and which have "total float" (i.e., can be delayed without making the project longer).

considering the above function of the cpm analysis because you have multiple path, there is tendency that more than path through the project network will have zero slack values.