Contouring Assignments

When you make a resource assignment, Project uses the default flat work contour and then spreads each unit’s effort evenly across the duration of the task. If, for example, a resource is assigned 100% to a 40-hour task with no predecessors, the task will begin immediately with 8 hours of work each day for five days. In Gantt Chart view, you can see a task’s duration.

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You can’t, however, see the detail showing how many hours of work will be completed each day within the duration. There are two views that show you how the work is distributed within an assignment: the Resource Usage view (refer to Figure 10.12) and the Task Usage view, shown in Figure 10.14.

The shape of the distribution of work within an assignment is the work contour. The work contour is not an attribute of the task or the resource—it is an attribute of the assignment. When the work is spread evenly, the contour is flat. The Flat contour is appropriate when the same amount of work should be done every day of the assignment. Some assignments, though, are different. Writing this book, for example required minimal work at the beginning (preparing an outline), followed by a huge amount of work (writing the text). The writing project then ramps down as editing continues, but the initial writing has been completed.

You can change the distribution of an assignment’s work by applying a predefined contour; or, you can edit the existing distribution or the distribution created when you applied a contour to create a custom contour.

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Figure 10.14: Use the Task Usage view to contour assignments.

Applying a Predesigned Contour

Unlike task type, there is no option to set a contour for the entire project. Every assignment uses the default Flat contour until you change it. Project 2002 includes eight predesigned contours as shown in Table 10.1.

Table 10.1: Project’s Predesigned Contours

Contour Type

Description

Flat (default)

Work distributed evenly

Back Loaded

Peak activity occurs at the end of the assignment

Front Loaded

Peak activity occurs at the beginning of the assignment

Double Peak

Work clusters around two periods of peak activity

Early Peak

Similar to Front Loaded, but with a ramp up to the peak activity

Late Peak

Similar to Back Loaded, but with a ramp down from peak activity

Bell

A single peak in the middle of the assignment

Turtle

A bell with ramp up and ramp down

To change the work contour for an assignment in either Task Usage or Resource Usage view, double-click an assignment to open the Assignment Information dialog box, select the General tab, and choose a contour from the Work Contour drop-down list:

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Contours interact with task and resource settings as you manage and adjust assignments during the life of the project. The contour shape is preserved with the assignment when you move the task or the project schedule changes.

Tip 

You can add the Work Contour column to the Resource Usage or Task Usage view, and change assignment contours in the view.

When you contour an assignment, Project applies the contour and recalculates work, duration, or units based on the task type of the assignment’s task. Before we discuss the effect of task types on contouring, let’s take a closer look at each of the eight predefined contours applied to a 40-hour work assignment to a task created with the default fixed units task type.

The Flat Contour

With the Flat contour, work is distributed evenly across the duration of the assignment. This is demonstrated in Figure 10.15, which shows the Task Usage view on top and the resource graph in the lower window. With Flat contouring, 50% of the assignment’s work is completed in the first half of the assignment duration.

The Back Loaded Contour

With a back-loaded assignment, the majority of the work is undertaken at the end of the assignment. Only 25% of the work is completed in the first half of the assignment’s duration. Preparation for an event such as a conference is generally back loaded as work increases when the event approaches. For back-loaded assignments, the back loading icon is displayed in the Indicators column. The effect of applying the Back Loaded contour is easily seen in Figure 10.16.

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Figure 10.15: The (default) Flat contour

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Figure 10.16: The Back Load contour

The Front Loaded Contour

Front loading an assignment places the majority of the effort at the beginning of the assignment, as shown in Figure 10.17. Seventy-five percent of the assignment’s work is completed halfway through the assignment duration. Select a Front Loaded contour when an assignment involves a significant startup effort and then slowly tapers off.

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Figure 10.17: The Front Load contour

Tip 

Contouring stores information that you’d have to track in your head or with a manual system in the assignment. If all assignments used the Flat contour, for example, you have to remember to be concerned when a front loaded assignment is only half complete at the 50% duration mark. Contouring assignments so that they reflect the actual workload of the assignment makes it easier for you to track and manage your project.

The Double Peak Contour

Apply the Double Peak contour to assignments that feature two major expenditures of effort with downtime in between. Halfway through a double-peak contoured assignment, 50% of the work should have been completed, but the assignee is past one of the two hurdles in the assignment. Figure 10.18 shows a 40-hour assignment with Double Peak contouring.

The Early Peak Contour

The Early Peak contour is similar to the Front Loaded contour, but activity starts more slowly. Seventy percent of the work is completed in the first half of the assignment’s duration, as shown in Figure 10.19.

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Figure 10.18: The Double Peak contour

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Figure 10.19: The Early Peak contour

The Late Peak Contour

The Late Peak contour is similar to the Back Loaded contour, but the peak activity is near, not at, the end of the assignment, and is followed by a rapid ramp-down. With late peak contouring, only 30% of the work is distributed in the first 50% of the assignment duration. (After the midway point, every day probably seems like Monday.) A 40-hour assignment with Late Peak contouring is shown in Figure 10.20.

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Figure 10.20: The Late Peak contour

The Bell Contour

Use Bell contouring when the assignment requires a rapid ramp up to a large expenditure of effort in a short burst at the midway point, followed by a rapid ramp down, as shown in Figure 10.21.

The Turtle Contour

The Turtle contour is like the Bell contour, but with caramel and peanuts. Just kidding. It’s actually similar to the Bell contour, but with faster ramping and a longer period of high activity, as shown in Figure 10.22. With Turtle contouring, the period of peak activity lasts twice as long as with Bell contouring.

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Figure 10.21: The Bell contour

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Figure 10.22: The Turtle contour

How Task Types and Contours Interact

Each predesigned contour adjusts the amount of work that will be done in each time period. The cumulative result will be a change in duration or work, depending on the task type of the task involved in the assignment. Contouring affects assignments, and holds units fixed while contouring. Consequently, contouring never adjusts units. In addition, an effort driven task setting is not a factor because effort driven scheduling applies when resources are added or removed from an assignment.

On the contrary, contouring adjusts the distribution of activity within the assignment. To see the effect of task type on contouring, we created three tasks, each of which has a 5-day duration, and assigned one full-time resource, Worker B (also known as Buzz). A section of the Task Usage view with the three assignments, prior to contouring, is shown in Figure 10.23.

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Figure 10.23: Three assignments prior to contouring

Now, we’ll contour each of the three assignments exactly by selecting all three and applying a Double Peak contour. The three contoured assignments are shown in Figure 10.24. For the fixed units and fixed work task types, contouring the assignment resulted in a change in duration. In the fixed duration task’s assignment, the duration could not be changed, so contouring reduced the hours of work in the assignment.

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Figure 10.24: The three assignments after applying Double Peak contour

Contours are applied to assignments, not to tasks or resources. If you have several resources assigned to a task, you can apply a different contour for each assignment. For an Exhibit at Trade Show task, for example, assignments for staff arriving early to set up could be front loaded, while assignments for staff staying after to break down the display could be back loaded.

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The Mathematics of Predefined Contours

When you apply any predesigned contour other than the default contour, Project determines the duration that will be required after contouring, splits the duration into 10 segments, and multiplies each segment by a percentage to determine the hours (minutes, days) of work to allocate to the segment. Table 10.2 shows the percentage of work that will be assigned for each segment of the predesigned contours and the average of the work in each segment.

For fixed units and fixed work tasks, before Project applies the percentages in the contour, it has to perform two additional calculations. First, Project divides the total work in the assignment (40 hours) by the average of the segment percentages for the selected contour (in the case of the Turtle contour, 70%) to determine the new duration for the assignment: 40 hours / 0.70 = 57 hours, or 7.14 days.

The additional 2.14 days’ duration is the result of assigning less work in the first three and last three segments to contour the task. Project then divides the duration into 10 segments, and allocates the work for each segment based on the percentage shown in Table 10.2.

With fixed duration tasks, duration can’t change so applying a contour results in a reduction in work.

To quickly calculate the new duration for fixed unit and fixed work tasks before applying a contour, divide the current duration by the average in the last column of the table. To calculate the new work value for fixed duration tasks, multiply the current work value by the percentage.

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Table 10.2: Contour Segment Percentages

Contour

1

2

3

4

5

6

7

8

9

10

Average

Flat

100%

100%

100%

100%

100%

100%

100%

100%

100%

100%

100%

Back Loaded

10%

15%

25%

50%

50%

75%

75%

100%

100%

100%

60%

Front Loaded

100%

100%

100%

75%

75%

50%

50%

25%

15%

10%

60%

Double Peak

25%

50%

100%

50%

25%

25%

50%

100%

50%

25%

50%

Early Peak

25%

50%

100%

100%

75%

50%

50%

25%

15%

10%

50%

Late Peak

10%

15%

25%

50%

50%

75%

100%

100%

50%

25%

50%

Bell

10%

20%

40%

80%

100%

100%

80%

40%

20%

10%

50%

Turtle

25%

50%

75%

100%

100%

100%

100%

75%

50%

25%

70%

Editing a Contour

When you manually change the work assignments in the Resource Usage or Task Usage view, the result is an edited contour. To edit a contour, switch to Resource Usage view or Task Usage view. In Resource Usage view, you can edit timephased work and the total work for any assignment. You cannot edit timephased or total work for a resource. In Task Usage view, you can edit timephased and total work values for assignments or tasks. Editing is as simple as entering new values for any day’s work.

When you edit a contour, the contour icon shows that it has been edited. If you double-click the assignment to open the Assignment Information dialog box, Contoured is listed as the Work Contour type.

Warning 

Edited contours don’t follow the same rules as the predesigned contours. There’s nothing to stop you from adding work to an assignment so that the task’s start date or finish date changes. To avoid accidentally changing a task’s start or finish date, don’t adjust the total work for an assignment in the Task Table pane on the left. Adjust timephased work only in the Timeline pane on the right.

Apply the predesigned contour that’s most like the contour you want to create. Click the timephased work cell you want to edit, and enter a new value. Project distributes the work based on the following rules:

  • If the work cell doesn’t include the start or finish of the assignment, the work value is distributed over the cell. For example, 4 hours of work are assigned throughout the day, and units are recalculated at 50%.

  • If the work cell includes both the assignment start and finish, work is distributed between the two. If the assignment starts at 8:00 a.m. and ends at 10:00 a.m., the 4 hours will be distributed in that 2-hour duration. This means that units will be adjusted to 200%.

  • If the work cell includes the start but not the finish, work is distributed from the start time or date. For example, if an assignment starts at 1:00 p.m., 4 hours of work are distributed from 1:00 p.m. to 5:00 p.m., and units are calculated at 100%.

  • If the work cell includes the assignment’s finish, the work is distributed up to the finish. For example, if the task assignment ends at 12:00 p.m., 4 hours of work are distributed from 8:00 a.m. until 12:00 p.m., and units are calculated at 200%.

Whenever you edit a contour, Project distributes the work within the duration and recalculates units. This recalculation isn’t obvious in either view. To see the change in units, double-click an assignment to open the Assignment Information dialog box and then examine the Units field on the General tab.

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Mastering Microsoft Project 2002
Mastering Microsoft Project 2002
ISBN: 0782141471
EAN: 2147483647
Year: 2006
Pages: 241

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