The Network Diagram

A network diagram is essentially a flow chart that includes all of the project elements and how they relate to one another. It is widely used because it is easy to read and not only depicts the sequence of activities in the project, but also shows parallel activities and the links between each activity. Network logic is the collection of activity dependencies that make up a network diagram for a particular project. In other words, certain tasks are dependent on one another to complete the project. This creates a logical stream of events that will lead to completion of the project.

You'll need to analyze, organize, and put into sequence the activities that need to be completed. You'll also need to carefully determine how long it should take to complete each task and in what order they will be performed. Setting up dependencies, or tasks that depend on the previous one being performed, will be vital to a smooth-flowing schedule. Setting deliverable dates — when tasks need to be completed or products delivered — will also be part of the equation.

Lining Up the Pieces

Even when doing a smaller personal project, it's important to have a schedule. You may be able to get by with a to-do list when planning a vacation or a party, but there is still a need to organize and prioritize. For example, you can't plan a trip to France without a passport for each family member. Because of the length of time it takes to receive a passport, this will need to be a high-priority item, scheduled early on in the sequence of events leading up to your trip. No matter what the project, the sequence of events is significant to completing the project.

A good project manager wears many hats. Identifying stakeholders and defining their roles, clarifying project objectives and goals, doing plenty of research, assessing skills, putting the team together, promoting effective communication between team members (and everyone else), monitoring the project, and about ninety-nine other tasks fall under your jurisdiction.

Determining dual tasks is also important. If a project has fifty tasks that would each take a week to complete, your initial estimate might be that the project would take one year to complete. However, if five tasks could be completed simultaneously every week, you'd have the project finished in ten weeks. Therefore, you need to carefully determine which tasks can be done simultaneously.

Refer to this diagram as you read through the chapter. As a visual and organizational aid, the diagram will help you plan and track dependencies and concurrent tasks.

The network diagram lets you do the following:

  • Define the project's path

  • Determine the sequence of tasks to be completed

  • Look at the relationship between activities

  • Determine the dependencies

  • Set up simultaneous tasks

  • Monitor your project by establishing benchmarks, milestones, or deliverables — these are markers to determine whether your project is on, ahead of, or behind schedule

  • Make adjustments as tasks are completed

  • Take a broad look at the project path and clearly see the relationships and dependencies between tasks

There are complicated network diagrams and simple ones that you can figure out at a glance. The ease with which you can follow the network diagram depends on how complex the project is and how well you have defined everything that appears on it. You can use one color to indicate the tasks that can be completed simultaneously and another color to highlight tasks that are dependencies, or dependent on the completion of a prior task.

Your network diagram will have a critical path, which is the route from start to end that must be completed to finish the project. This is the spine, or what drives the network diagram. The activities that need to be completed along the critical path and all other paths (which ultimately connect to the critical path) are typically connected with lines and arrows. Then you will label the activity. As activities are completed, you should clearly mark them completed or highlight them in another color or manner. Each activity should include the number of days it will take to complete the task.

Elapsed time or duration is how much real time is needed to complete an activity. A consultant may estimate he'll need twelve hours to do a task, but he probably won't work twelve hours straight. If he works four hours a day for three days, the duration or elapsed time is three days, so you'll need to factor three days into your schedule for the task to be completed.

The benefits of the network diagram are that you can see not only the tasks that need to be done, but how long they should take to complete and where they are in relationship to one another. Each task is defined in a box, and the boxes are laid out horizontally to show the sequence of tasks. Two rows (or more) of parallel boxes indicate that these tasks are taking place simultaneously.

A good network diagram, like a treatment for a screenplay, blueprints for an engineer, or a game plan for a football team, includes all the details that need to be taking place. This allows you to get a good estimate of how long the activities should take and helps you monitor the flow of the project on a task-by-task basis. You can easily see where you might have to add more time or manpower, or where the flow of activity in one area is ahead of another. When putting together a museum guidebook, you might have writers creating copy while photographers are taking photos. You'll be able to see that the photographers have completed taking the pictures, while the writers have not yet completed their first drafts. Therefore, you may need to call in another writer.

Building Your Network Diagram

No matter what the scope of the project is, unless it's a one- or two-person operation with few individual tasks involved, it's helpful to have something on paper. Build yourself a little network diagram and use it as your guide. If nothing else, it will give you a sense of accomplishment as you color in each task en route to your conclusion. Anyone who has ever tried a serious diet (one approved by a doctor and not a fad diet) knows the benefit of celebrating milestones along the way to achieving their project goal. If your goal is losing twenty pounds in a month, then every five pounds lost may serve as a milestone along the way.

The network diagram doesn't place tasks in order of what is more important or more costly to complete. Sometimes the most important task (which might be judged by difficulty to accomplish, significance to other tasks being completed, or simply by time or cost) comes at the beginning of the project and everything else is the icing on the cake. In other projects, all the preliminaries, such as planning the wedding, lead to the main event.

While a diet is a uniquely individual project, you can set it up for yourself horizontally on a network diagram just as you would for any business, community, or home-based project. To set up the diagram, you take the list of all the tasks involved and see which ones must be accomplished before moving on to other tasks and which ones can be done independently of each other. A museum guidebook, however, is more team oriented, and its diagram would first include the tasks that the writers needed to do along with the tasks the photographers needed to do, plus perhaps a third column of tasks ad sales representatives needed to do. At first, the ad sales reps are dependent on some initial copy and graphics being completed so they have something to show sponsors. Then all three — the writers, photographers, and sales staff — can work simultaneously until the material needs to come together and be presented to the printer. Along the way, you might want to select specific milestones, such as an outline from the writers, a list of photos from the photographers, or a list of local retailers to contact for advertisements.

What is a milestone?

A milestone in a network diagram is a box that defines a task or series of tasks that have been completed. These are checkpoints that you can look at to see whether you are or aren't on schedule. Milestones may, and often do, include deliverables.

If you're working on paper, use a pencil and eraser. Be prepared to rewrite your diagram a few times until you've included everything in sequential order with milestones and all. Look at the sample network diagram to guide you. On a computer program, you'll be entering and reentering your information a lot.

Reviewing Your Network Diagram

Once you've completed your network diagram, review it carefully before hanging it on the wall like a Picasso (believe me, when you're done, it will feel like you've created a masterpiece). Check to make sure all the activities on your detailed task list are included and be sure the sequence makes sense. Remember, you can't edit the museum-guide copy if you haven't written it yet. If several tasks taking place simultaneously need to be finished before a next step can be started, make sure all arrows from the first tasks lead to the second. In other words, the tasks of writing, photography, and ad sales all have to be completed before the box that says “take to the printer,” so all of these activities lead to the same final box.

It's really pretty simple once you start putting it on paper. In fact, why not fill in a blank network diagram with a task you'd like to accomplish? First, however, you need to make a simple work breakdown sheet for yourself on a piece of paper listing the tasks needed to complete your project. Then, start filling in the network diagram. Feel free to add more boxes if necessary, and don't forget to pencil in your milestones in some of the boxes. (Remember, milestones are simply signposts that let you mark your progress.)

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