Activity Sequencing is a time management planning process used to determine how the work of project will progress. In other words, it is the sequence of the tasks of the project. In Activity Sequencing you take the activity list created by the work breakdown structure, then use tools an techniques to decide on the progression of the work, which results in the creation of a network diagram.
In order to begin the sequencing process, you must first understand the elements that make it possible, including activity lists, dependencies, and diagramming methods.
In the last chapter, we talked about the lowest level of work on the WBS. That lowest level is cal work package. It is also called the activity list.
The first component of Activity Sequencing is determining the dependencies of the work to be di dependency describes the relationship between two tasks. There are three types of dependence They are:
Mandatory dependencies Are inherent in the work to be done. You cannot road test a new tire the tire is manufactured.
Discretionary dependencies Created by the project team. On the new tire you are creating, yc want a 1/2-inch tread. Because of the size of the tread, you'll need to use a new tire mold that wo ready for six weeks. You've just created a discretionary dependency.
External dependencies Come from outside of your project. On your new tire, you are using a s rubber formula that is being shipped from Japan. The next ship to leave for the United States do leave for two more days. You now have an external dependency on that shipment.
Once you understand dependencies, you will need to know which tool and technique to use to d the sequence of the work. There are two diagramming methods that are most commonly used f sequencing. The first is the precedence diagramming method (PDM), also known as activity on n (AON). In this type of diagram, shown in Figure 2.2, the nodes (boxes) depict the task and the ar depict the dependency.
Precedence diagramming uses four types of logical relationships to determine the dependencie between the activities. They are:
1. In the finish to start relationship, illustrated in Figure 2.2 Activity B cannot start until Activity completed.
2. In the start to finish relationship, illustrated below, Activity B cannot finish until Activity A ha started.
3. In the finish to finish relationship, pictured below, Activity B cannot be completed until Acti is completed.
4. Finally, in the start to start relationship, Activity B cannot start until Activity A starts. The following is an example of the start to start relationship.
The other commonly used diagramming method is the arrow diagramming method (ADM), also known as activity on arrow (AOA). In this method, the lines are the activities and the circles are tl nodes that depict the relationship. The arrow diagramming method, shown in Figure 2.3, uses a to start relationship.
Figure 2.3: Arrow diagramming method
Once you know the components of Activity Sequencing, you can create a network diagram, like one shown in Figure 2.4, which depicts the progression of work on a project. You will need to cr< start and finish node so that all nodes on the network diagram are connected.
Figure 2.4: Network diagram
Figure 2.4: Network diagram
Here are the steps to make a network diagram using Activity Sequencing.
1. Determine whether the WBS needs to be decomposed into smaller activities, called an ac list. These should be small activities that can be assigned to one person.
2. Understand each activity well enough to determine the dependencies between them. Are mandatory, discretionary, or external?
3. Determine the method of diagramming you will use: precedence or arrow diagramming.
4. Understand the dependencies well enough to know the type of logical relationship betwe activities.
6. Sequence the lowest level activities or tasks between the start and finish nodes. Do not sequence the higher levels of the work breakdown structure, that is, the summary level activities.
Note Recommended Reading: Chapter 5, pp. 165-169, PMP Project Management Profess Study Guide.
In Exercise 2.2, you're going to continue your work with SystemsDelivery on the credit card valid; project, by determining dependencies and logical relationships and by choosing diagramming methods to create a network diagram.
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