Three types of dependencies are used to define the sequence among the activities.
• Mandatory dependencies. The project management team determines which dependencies are mandatory during the process of establishing the sequence of activities. Mandatory dependencies are those that are inherent in the nature of the work being done. Mandatory dependencies often involve physical limitations, such as on a construction project, where it is impossible to erect the superstructure until after the foundation has been built, or on an electronics project, where a prototype must be built before it can be tested. Mandatory dependencies are also sometimes referred to as hard logic.
• Discretionary dependencies. The project management team determines which dependencies arc discretionary during the process of establishing the sequence of activities. Discretionary dependencies arc fully documented since they can create arbitrary totai float values and can limit later scheduling options. Discretionary dependencies arc sometimes referred to as preferred logic, preferential logic, or soft logic. Discretionary dcpcndcncics arc established based on knowledge of best practices within a particular application area or some unusuai aspect of the project where a specific sequence is desired, even though there may be other acceptable sequences. Some discretionary dcpcndcncics includc preferred schedule activity scqucnccs based upon previous cxpcricncc on a successful project performing the same type of work.
• External dependencies. The projcct management team identifies external dcpcndcncics during the process of establishing the sequence of activities. External dependencies are those that involve a relationship between projcct activities and non-project activities. For example, the testing activity in a software projcct can be dependent on the 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 188.8.131.52) from previous projects of a similar nature or from seller contracts or proposals (Section 184.108.40.206).
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What you need to know about… Project Management Made Easy! Project management consists of more than just a large building project and can encompass small projects as well. No matter what the size of your project, you need to have some sort of project management. How you manage your project has everything to do with its outcome.