Project Planning

Project schedule development

Now were off and running toward the development of our project schedule. In order to develop our schedule, we first need to define the activities, sequence them in the right order, estimate resources and estimate the time it will take to complete the tasks.

The activity definition process is a further breakdown of the work package elements of the WBS. It documents the specific activities needed to fulfill the deliverable detailed in the WBS. These are not deliverables but the individual units of work that must be completed to fulfill the deliverables. Activity definition uses everything we already know about the project to divide the work into activities that can be estimated. You might want to look at all the lessons learned from similar projects your company has done to get a god idea of what you need to do on the current one.

Expert judgment in the form of project team members with prior experience developing project scope statements and WBS can help you define activities. You might also use experts in a particular field to help define tasks if you were asked to manage a project in a new domain; to help you understand what activities were going to be involved. It could be that you create an activity list and then have the expert review it and suggest changes. Alternatively, you could involve the expert from the very beginning and ask to have an activity definition conversation with him before even making your first draft of the list.

Sometimes you start a project without knowing a lot about the work that you'll be doing later. Rolling wave planning lets you plan and schedule only the stuff that you know enough about to plan well. When you don't know enough about a project to come up with a complete activity list, you can use a planning component as a placeholder until you know more. These are extra items put at high levels in the WBS to allow you to plan for the unknown.

A case study

Susan and Steve have decided to tie the knot, but they don't have much time to plan their wedding. They want the big day to be unforgettable. They want to invite a lot of people and show them all a great time. They've always dreamed of a June wedding, but it's already January. Just thinking about all of the details involved is overwhelming. Somewhere around picking the paper for the invitations, the couple realizes they need help. Susan's been dreaming of the big day since she was 12, but it seems like there's so little time to do it all.

Susan: Steve, we need some help.
Steve: Don't worry. My sister's wedding planner was great. Let me give her a call. [Steve calls the wedding planner Sally].
Wedding Planner: Hello, Susan and Steve.
Steve: We want everything to be perfect.
Susan: There is so much to do! Invitations, food, guests, and music.
Steve: Oh no, we haven't even booked a place!
Susan: And it has to be done right. We can't print the invitations until we have the menu planned. We can't do the seating arrangements until we have the RSVPs. We aren't sure what kind of band to get for the reception, or should it be a DJ? We're just overwhelmed.
Steve: My sister said you really saved her wedding. I know she gave you over a year to plan. But I've always dreamed of a June wedding, and I'm not willing to give that up. I know it's late, but Sally, can you help us?
Wedding Planner: Take it easy. I've got it under control. We've a lot of people and activities to get under control. You really should have called six months ago, but we'll still make this wedding happen on time.

There's a lot to get done before June. Sally's going to need to figure out what work needs to done before she does anything else. For this she starts to put together a to-do-list.

• Invitations
  
• Flowers
• Wedding Cake
• Dinner Menu
• Band
  

Since there are so many different people involved in making the wedding go smoothly, it takes a lot of planning to make sure all of the work happens in the right order, gets done by the right people and doesn't take too long. Initially, Sally was worried that she didn't have enough time to make sure everything was done properly. But she knew that she had some powerful time management tools on her side when she took the job, and they'Il help her make sure that everything will work out fine.

To get started, Sally started arranging the activities in a work breakdown structure. This is part of the WBS Sally made for the wedding.

Exercise 1:

Arrange the following activities into the WBS to show how the work items decompose into activities.

• Shop for shoes
• Create guest list
• Tailoring and fitting
  
• Shop for dress
• Find caterer
• Cater the wedding
  
• Wait for RSVPs
  
• Mail the invitations
• Finalize the menu
• Print the invitations
• Choose the bouquet
  

Activity definition

Now that the activity definitions for the work packages have been completed, the next task is to complete the activity list. The project activity list is a list of everything that needs to be done to complete your project, including all the activities that must be accomplished to deliver the work package. Next you want to define the activity attributes. Here's where the description of each activity is kept. All of the information you need to figure out; the order of the work should be here too. So any predecessor activities, successor activities or constraints should be listed in the attributes along with descriptions and any other information about resources or time that you need for planning. The three main kinds of predecessors are finish- to-start (FS), start-to-start (SS) and finish-to-finish (FF).

The most common kind of predecessor is the finish-to-start. It means that one task needs to be completed before another one can start. When you think of predecessors, this is what you usually think of, one thing needs to end before the next can begin. It's called finish-to-start because the first activity finish leads into the second activity's start (Figure 7).

Figure 7: An example of a finish-to-start (FS) predecessor.

The start-to-start predecessor is a little less common, but sometimes you need to coordinate activities so they begin at the same time  (Figure 8).

Figure 8: An example of a Start-to-start (SS) predecessor.

In the finish-to-finish predecessor it shows activities that finish at the same time (Figure 9).

Figure 9: An example of a finish-to-finish (FF) predecessor.

It is possible to have to have start-to-finish (SF) predecessors. This happens when activities require that a task be started before it can finish. An example might be that singing couldn't start until after the music had started. Keep in mind that tasks like that are pretty rare and almost never show up in network diagrams. In addition there are some particular types of predecessors that must be considered.

External predecessors

Sometimes your project will depend on things outside the work your doing. For the wedding, we are depending on the wedding party before us to be out of the reception hall in time for us to decorate. The decoration of the reception hall then depends on that as an external predecessor.

Discretionary predecessors

These are usually process or procedure driven or "best practice" techniques based on past experience. Using the wedding example: Steve and Susan really want the bridesmaids to arrive at the reception before the couple. There's no necessity there- it's just a matter of preference.

Mandatory predecessors

You can't address an invitation that hasn't been printed yet. So, printing invitations is a mandatory predecessor for addressing them. Mandatory predecessors are the kinds that have to exist just because of the nature of the work.

Leads and lags

Sometimes you need to give some extra time between activities. Lag time is when you purposefully put a delay between the predecessor task and the successor. For example, when the bride and her father dance, everybody waits a while before they join them (Figure 10).

Figure 10: A lag means making sure that one task waits a while before it gets started.

Lead time is when you give a successor task some time to get started before the predecessor finishes (Figure 11). So you might want the caterer preparing dessert an hour before everybody is eating dinner.

Figure 11: A lead is when you let a task get started before its predecessor is done.

Milestones

All of the important checkpoints of your project are tracked as milestones. Some of them could be listed in your contract as requirements of successful completion; some could just be significant points in the project that you want to keep track of. The milestone list needs to let everyone know which are required and which are not.

Some milestones for Susan and Steve's wedding might be:

• Invitations sent
•  Menu finalized
  
• Location booked
  
• Bridesmaids'dresses fitted
  

As you figure out which activities will need to be done, you may realize that the scope needs to change. When that happens, you need to create a change request and send it through the change control system. So back to our couple and their nuptial plan.

Wedding Planner: We just got the programs back from the printer and they're all wrong.
Steve: The quartet cancelled. They had another wedding that day.
Susan: Aunt Jane is supposed to sing at the service, but after what happened at her uncle's funeral, I think I want someone else to do it.
Steve: Should we really have a pan flute player? I'm beginning to think it might be overkill.
Susan: Apparently! Maybe we should hold off on printing the invitations until these things are worked out.
Wedding Planner: OK, let's think about exactly how we want to do this. I think we need to be sure about how we want the service to go before we do any more printing.

The activity sequencing process

Now that we know what we have to do to make the wedding a success, we need to focus on the order of the work. Sally sat down with all of the activities she had defined for the wedding and decided to figure out exactly how they needed to happen. That's where she used the activity sequencing process.

The activity attribute list Sally created had most of the predecessors and successors necessary written in it. This is where she thought of what comes first, second, third, etc. Sally's milestone list had major pieces of work written down and there were a couple of changes to the scope she had discovered along the way that were approved and ready to go.

Example 5:

Milestone list: Steve and Susan had asked that the invitations be printed at least three months in advance to be sure that everyone had time to RSVP. That's a milestone on Sally's list.

Example 6:

Change request: When Sally realized that Steve and Susan were going to need another limo to take the bridesmaids to the reception hall, she put that change through change control- including running everything by Susan's mother- and it was approved.

Creating the network diagram

The first step in developing the schedule is to develop a network diagram of the WBS work packages. The network diagram is a way to visualize the interrelationships of project activities. Network diagrams provide a graphical view of the tasks and how they relate to one another. The tasks in the network are the work packages of the WBS. All of the WBS tasks must be included in the network because they have to be accounted for in the schedule. Leaving even one task out of the network could change the overall schedule duration, estimated costs and resource allocation commitments.

The first step is to arrange the tasks from your WBS into a sequence (Figure 12). Some tasks can be accomplished at any time throughout the project where other tasks depend on input from another task or are constrained by time or resources.

Figure 12: The relationship between the work breakdown structure (WBS) and the network diagram.

The WBS is not a schedule, but it is the basis for it; the network diagram is a schedule but is used primarily to identify key scheduling information that ultimately goes into user friendly schedule formats, such as milestone and Gantt charts.

The network diagram provides important information to the project team. It provides information about how the tasks are related (Figure 12), where the risk points are in the schedule, how long it will take as currently planned to finish the project, and when each task needs to begin and end.

In our wedding planner example, Sally would look for relationships between tasks and determined what can be done in parallel and what activities needed to wait for others to complete. As an example, Figure 13 shows how the activities involved in producing the invitations depend on one another. Showing the activities in rectangles and their relationships as arrows is called a precedence diagramming method (PDM). This kind of diagram is also called an activity on node (AON) diagram.

Figure 13: An example of an activity on node (AON) diagram.

Another way to show how tasks relate is with the activity-on-arrow (AOA). Although activity-on-node (AON) is more commonly used and is supported by all project management programs, PERT is the best-known AOA-type diagram and is the historical basis of all network diagramming. The main difference is the AOA diagram is traditionally drawn using circles as the nodes, with nodes representing the beginning and ending points of the arrows or tasks. In the AOA network, the arrows represent the activities or tasks (Figure 14).

Figure 14: An example of an activity-on-arrow (AOA) network diagram.

All network diagrams have the advantages as showing task interdependencies, start and end times, and the critical path (the longest path through the network) but the AOA network also has some disadvantages that limit the use of the method.

The three major disadvantages of the AOA method are:

• The AOA network can only show finish to start relationships. It is not possible to show lead and lag except by adding or subtracting time, which makes project tracking difficult.
  
• There are instances when dummy activities can occur in an AOA network. Dummy activities are activities that show the dependency of one task on other tasks but for other than technical reasons. For example, a task may be dependent on another because it would be more cost effective to use the same resources for the two; otherwise the two tasks could be accomplished in parallel. Dummy activities do not have durations associated with them. They simply show that a task has some kind of dependence on another task.
  
• AOA diagrams are not as widely used as AON simply because the latter are somewhat simpler to use and all project management software programs can accommodate AON networks, whereas not all can accommodate AOA networks.