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Project Management – Sequence Activities Process
By Marc Derendinger, Northwest University

The sequence activities process takes all the activities you defined in the Define Activities process and orders them by precedence. You are creating a map or diagram that illustrates the relationship between these activities and identifying the order in which they need to be done. It is important to note that you are not creating the schedule itself during this process, and therefore do not assign any start or finish dates to these activities.

Your inputs for this process include: activity list, activity attributes, milestone list, project scope statement and organizational process assets. Your activity list contains your schedule activities and needs to be arranged into the order they should be performed for your diagram. Your activity attributes provides additional insight into which activities need to be performed before others. Your milestone list provides you with key milestones that might influence the order of your activities. For example, if you have a milestone of a pre-release beta of a software program you are creating, you might need to complete your model rendering and shading activities sooner than you would need to otherwise to create a more user friendly interface.

Your project scope statement helps you ensure nothing is missed, and could often influence your activity performance order. For instance, if you were to create a garden that was open to the public, you might need to recruit human resource personnel before organizing a volunteer event. Your organizational process assets exist to help in case there is some relevant information from a similar project that could facilitate your prioritizing these activities more efficiently.

There are four tools used in this process: Precedence Diagramming Method (PDM), dependency determination, apply leads and lags and schedule network templates. The PDM creates a graphical representation of your activities list and the order they must be performed. This diagram is often shown as a simple flow chart, with rectangles representing activities, the arrows their dependencies and units of duration listed above the nodes.

Determining your dependency can be more difficult, but there exist three kinds of dependencies: mandatory, discretionary and external. A mandatory dependency is one that cannot be broken. These are known as hard logic, considered unavoidable and always true. For example, you need to dig a hole before you can pour a concrete form for your swimming pool. Discretionary dependencies are not always true, and known as soft logic. Typically your best practices will determine these dependencies, as well as expert judgment and historical information. An example might be choosing to slice a tomato before slicing a cucumber for your salad, when either could take precedence. External dependencies are outside the project’s control and scope, but must be considered. For instance, if you are constructing a building to LEED Leadership in Energy and Environmental Design standards, but these standards are undergoing a revision you might have an external dependency until this revision occurs.

Sometimes an activity can get a jump start on another, or there needs to be a waiting period between activities; these are known as leads and lags. A lead happens when one activity provides the resources to start a dependent activity, but hasn’t quite finished yet. For instance, an event requires your music to be decided out before finding a D.J. A lead could occur when you know what genre of music you will use and can find a D.J. who is known to be proficient in that genre, but the music still needs to be picked out. A lag is when there is a waiting period between two activities, such the wait time for paint to dry before hanging decorations in a building’s interior.

Your outputs from this process are your project schedule network diagrams and any project document updates as necessary. Your network diagram is not your schedule, merely a representation of activity dependencies. Your schedule is developed in a different process. This diagram can include summary nodes of your activities, or a complete representation of all activities, depending on your needs. Should summary nodes be used, you should provide enough documentation to ensure the basic flow of activities is understood.

Northwest University opened to students on October 1, 1934. It is a regionally accredited institution awarding associate, baccalaureate, and master’s degrees.

Note: Implicit permission was given to republish this post, as the article was not copyrighted.

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