Activity Definition: Tools and Techniques

• Discretionary dependencies. The project management team determines which dependencies are discretionary during the process of establishing the sequence of activities. Discretionary dependencies are fully documented since they can create arbitrary total float values and can limit later scheduling options. Discretionary dependencies are sometimes referred to as preferred logic, preferential logic or soft logic. Discretionary dependencies are usually established based on knowledge of best practices within a particular application area or some unusual aspect of the project where a specific sequence is desired, even though there are other acceptable sequences. Some discretionary dependencies include preferred schedule activity sequences based upon previous experience on a successful project performing the same type of work. • External dependencies. The project management team identifies external dependencies during the process of establishing the sequence of activities. External dependencies are those that involve a relationship between project activities and non-project activities. For example, the testing schedule activity in a software project can be dependent on delivery of hardware from an external source, or governmental environmental hearings may need to be held before site preparation can begin on a construction project. This input can be based on historical information Section 4.1.1.4 from previous projects of a similar nature or from seller contracts or proposals Section 12.4.3.2. .5 Applying Leads and Lags The project management team determines the dependencies Section 6.2.2.4 that may require a lead or a lag to accurately define the logical relationship. The use of leads and lags and their related assumptions are documented. A lead allows an acceleration of the successor activity. For example, a technical writing team can begin writing the second draft of a large document the successor activity fifteen days before they finish writing the entire first draft the predecessor activity. This could be accomplished by a finish-to-start relationship with a fifteen-day lead time. A lag directs a delay in the successor activity. For example, to account for a ten-day curing period for concrete, a ten-day lag on a finish-to-start relationship could be used, which means the successor activity cannot start until ten days after the predecessor is completed. A Guide to the Project Management Body of Knowledge PMBOK ® Guide Third Edition 134 2004 Project Management Institute, Four Campus Boulevard, Newtown Square, PA 19073-3299 USA

6.2.3 Activity Sequencing:

Outputs .1 Project Schedule Network Diagrams Project schedule network diagrams are schematic displays of the project’s schedule activities and the logical relationships among them, also referred to as dependencies. Figures 6-5 and 6-6 illustrate two different approaches to drawing a project schedule network diagram. A project schedule network diagram can be produced manually or by using project management software. The project schedule network diagram can include full project details, or have one or more summary activities. A summary narrative accompanies the diagram and describes the basic approach used to sequence the activities. Any unusual activity sequences within the network are fully described within the narrative. 6 .2 Activity List Updates If approved change requests Section 4.4.1.4 result from the Activity Sequencing process, then the activity list Section 6.1.3.1 is updated to include those approved changes. .3 Activity Attributes Updates The activity attributes Section 6.1.3.2 are updated to include the defined logical relationships and any associated leads and lags. If approved change requests Section 4.4.1.4 resulting from the Activity Sequencing process affect the activity list, then the related items in the activity attributes are updated to include those approved changes. .4 Requested Changes Preparation of project logical relationships, leads, and lags might reveal instances that can generate a requested change Section 4.4.3.2 to the activity list or the activity attributes. Examples include where a schedule activity can be divided or otherwise redefined, where dependencies can be refined, or where a lead or lag is adjusted to adequately diagram the correct logical relationships. Requested changes are processed for review and disposition through the Integrated Change Control process Section 4.6.

6.3 Activity Resource

Estimating Estimating schedule activity resources involves determining what resources persons, equipment, or materiel and what quantities of each resource will be used, and when each resource will be available to perform project activities. The Activity Resource Estimating process is closely coordinated with the Cost Estimating process Section 7.1. For example: • A construction project team will need to be familiar with local building codes. Such knowledge is often readily available from local sellers. However, if the local labor pool lacks experience with unusual or specialized construction techniques, the additional cost for a consultant might be the most effective way to secure knowledge of the local building codes. A Guide to the Project Management Body of Knowledge PMBOK ® Guide Third Edition 2004 Project Management Institute, Four Campus Boulevard, Newtown Square, PA 19073-3299 USA 135