Understanding Schedule Dependencies
Generally, an activity needs a time period with the determined start and end date. begins. It is very important to preserve the logical relationship in the network. The other 3 Logical Relationships are Finish to Start, Finish to Finish and Start to you to buy detailed PMP Exam Formula Study Guide by Cornelius Fichtner. A dependency is a logical relationship between two project activities in which the End-to-Start: The start date of the successor activity is based on the end date of the Successor. End-to-Start on Develop Activity. 2 days. Unit Test. 5 days.
The independent activity in the relationship must finish before the dependent activity can finish. This says that where there are two activities connected by an arrow, the one that is connected to the tail of the arrow must finish before the activity connected to the head of the arrow is allowed to finish.
It does not say that the dependent activity must finish then. The activity could finish later than that time, but it is not allowed to finish any sooner than the finish of the independent activity. For example, using the example of applying the frosting to the wedding cake, I must have the master chef there until the frosting is complete so that he or she can approve it. The master chef is then restricted from finishing the supervising activity until the frosting activity is finished.
The two activities are: The finish-finish relationship says that the master chef cannot finish supervising the cake construction until the frosting is completed. Notice that I could, logically, have the master chef continue supervising after that.
What’s an Example of a Start-to-Finish Relationship?
The relationship constricts the finish of the master chef supervising activity to be no sooner than the finish of the frosting activity. Start-Finish Relationship SF The start-finish relationship is very seldom used and has even been dropped from some of the project management scheduling software packages.
This relationship is stated in the same sentence as the finish-start relationship except that the words start and finish are substituted for finish and start. The independent activity in the relationship must start before the dependent activity can finish.
This says that where there are two activities connected by an arrow, the one that is connected to the tail of the arrow must start before the activity connected to the head of the arrow is allowed to finish. The dependent activity could finish later than that time, but it is not allowed to finish any sooner than the start of the independent activity.
For an example, using the wedding cake example again, the project is still to construct a wedding cake, and the activity is to apply the frosting to the cake. We do not want to finish applying the frosting to the cake until the master chef is on the scene. Remember that the start-start relationship says that I cannot start putting the frosting on the cake until I have the master chef present.
The start-finish relationship says that I can start putting on the frosting of the cake before the master chef is present, but I am not allowed to finish putting on the frosting until the master chef has started supervising.
The Practice Standard for Scheduling recommends, that "Typicallyeach predecessor activity would finish prior to the start of its successor activity or activities known as finish-to-start FS relationship. Sometimes it is necessarily to overlap activities; an option may be selected to use start-to-start SSfinish-to-finish FF or start-to-finish SF relationships Whenever possible, the FS logical relationship should be used.
If other types of relationships are used, they shall be used sparingly and with full understanding of how the relationships have been implemented in the scheduling software being used. Ideally, the sequence of all activities will be defined in such a way that the start of every activity has a logical relationship from a predecessor and the finish of every activity has a logical relationship to a successor".
Microsoft recommends to use SF dependency for just-in-time scheduling. There are three kinds of dependencies with respect to the reason for the existence of dependency: This blog focuses on establishing and managing dependencies that are understandable and create a reasonable workflow. This discussion includes using project management tools like MS Project to efficiently define and managing dependencies within your project schedule. Type of Dependencies Understanding the types of dependencies inherent in the work that needs to be completed is one of the most important elements of creating a strong project schedule.
There are 3 primary types of dependencies: Mandatory Dependencies — These are dependencies that create firm relationships between two activities.
Examples of this logic include: This activity cannot start until another activity finishes. These types of dependencies enable the team to optimize the flow of work throughout the project life cycle. Examples of this logic includes: This activity will happen at the same time as another group of activities. This activity will start up a couple weeks after another activity is completed. External Dependencies — These are dependencies that are outside the control of the project team, but nonetheless must be reflected in the project schedule.
Examples of external dependencies include: