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In order to calculate the late start and late finish dates for the critical path, refer to the two boxes in the bottom
row of the key in Figure 5-7. The latest date on which each task can finish (LF) is the late start of the
succeeding task. The latest date on which each task can start (LS) is the late finish of the preceding task minus
the elapsed time. For example, the sample project ends at Month 10, so the late finish for each of the final
tasks, I and J, in our example is 10 (Figure 5-7). The latest that each task could be started is the late finish of
the task minus its elapsed time. For example, Task I has a late finish of 10 and a late start of 8.5, which was
derived by subtracting its elapsed time, 1.5, from the late finish, 10. Moving backward on the path, the late
finish of Task F is the late start of Task I, or 8.5.
There is one more important calculation to make regarding the sequence of tasks surrounding the critical path:
float. Float is the leeway time existing within noncritical path tasks. Technically, float is the difference
between the late finish and early finish times for tasks on noncritical paths. In Figure 5-7, the float
calculations for each task are recorded in the top right-hand corner of the bottom quadrant. For Task J, the
float is 1.0 month (late finish of 10.0 months minus early finish of 9 months). Keep in mind that float occurs
only on noncritical paths. Did you notice that the ES, EF and LS, LF are the same for tasks on the critical
path? Also, two or more tasks on the same noncritical path will calculate the same float, which they must
share. So the float time of 1.5 months for Tasks C and F must be shared between them, and the float time of
2.5 months for Tasks D and G must be shared.




Figure 5-7. Development of early start, early finish, late start, and late finish.

Scheduling
The major objective of a schedule, sometimes referred to as a Gantt chart, is to place the data from the
previous four techniques”the WBS, the network, the estimates, and the critical path analysis”on a time
scale. In order to develop a comprehensive time scale, it is important that we see when work tasks start and
end, which are critical path tasks, which tasks have float and where it has been allocated, and what the
dependencies of tasks are to one another.
In order to plot the schedule, use a calendar format similar to the one shown in Figure 5-8. The units of time
are recorded along the horizontal axis and the task identifications are recorded along the vertical axis. In our
example, we have ten months of time and ten work tasks (A-J). Beginning with the critical path, plot Task A
on the schedule with an up-triangle indicating the early start (zero in this case) and a horizontal line drawn to
a down-triangle indicating the early finish (one month). Continue plotting the tasks on the critical path (B, E,
and H), being sure to connect each work task vertically with its immediate predecessor(s). When you come to
the first critical path work task that has input from a noncritical path(s) (Task I in our example), plot the
parallel noncritical paths (C, F and D, G) before plotting this next task. Use slash lines to depict the float at
the end of the noncritical path(s), unless you have determined another special allocation. In our example, the
float for Tasks C and F (1.5 months) begins at the end of Task F (Month 7) and continues to Month 8.5.
Similarly, the float for Tasks D and G (2.5 months) begins at the end of Task G (Month 6) and continues to
Month 8.5. Work in this fashion until all activities have been translated to the schedule. In this way, we have
planned to complete the tasks (except Task J) as soon as possible and to use the float at the end of our project.
We have decided to put Task J on its late schedule since training is best done just before people need to use
the skills. As a result, Task J is now added to the critical path.
Initially, during planning, the float can be used as a buffer to manipulate the schedule to be more compatible
with resource availability. Later, during monitoring and controlling, float tells you when a particular task may
be in jeopardy. If a task has no float, it is on the critical path. If a task has slipped, using up all of its float, it is
behind schedule, and you must find a way to recoup that time on the critical path. If the task has float and it is
behind schedule, watch that task carefully. If the task has used all its float time and is stretching beyond that,
recognize that it has become a critical task, with a changed critical path, and will affect the completion of the
total project. Not only must you ensure that this activity is completed as quickly as possible, but those
responsible for succeeding activities dependent on that late task must be informed. The lost time must be
made up in one of the succeeding activities to complete the project on time.




Figure 5-8. Project schedule.


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Project Management
by Joan Knudson and Ira Bitz
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ISBN: 0814450431 Pub Date: 01/01/91

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Resource Loading
Title

Resource loading is used to determine how resources will be allocated over the duration of a project and how
to verify that they are being allocated correctly. In other words, the purpose is to ensure that no team members
are ever overloaded. There are several options to determine resource loading:
-----------
1. Verify by name of employee that the number of activities (or projects) any one person (or pool) is
working on simultaneously is reasonable. For example, according to the diagram shown in Figure 5-9,
Marie Scotto (MS) appears to be very busy during the middle of the project.
2. Sum the percentage of time each team member plans to commit to each activity (or project) in a
single time frame in order to determine a total percentage greater than or less than the time the
individual has available. The diagram shown in Figure 5-10, for example, indicates that MS has
scheduled 150 percent of her time between Months 9.5 and 10 (summing vertically during this time
period would give us 50 percent of her time on Task I and 100 percent of her time on Task J).
3. Calculate the individual effort allocation for each team member. The diagram shown in Figure 5-11
points out that Marie™s time will be spent working on Tasks A, B, D, E, G, I, and J. The individual
effort estimate for her time on each of these tasks is posted vertically in the boxes falling under her
name. For example, her individual effort estimate for Task A is .1. This means that Marie will be
spending .1 effort months on this task. The total effort estimate of 1.0 for all team members is located
in the top box under the column heading Total Effort Estimate.
For the example, we have chosen to use 1.0 as a standard figure to represent forty hours of work, or one
week. This estimated forty hours of total effort for Task A is determined by summing the individual
effort estimates of the team members who will be working on this task”in this case, Joan™s .5 (twenty
hours) and the .1 estimate for the remaining team members (Bob, Guy, Marie, Jean, and Seth). If we
take this individual effort estimate for each team member on each task and divide it by the elapsed time
for the task, we will have calculated individual effort allocation. We will have dispersed the estimate of
each team member™s effort time over the elapsed time of the task. As a result, we now have a precise
measure for determining how team members™ times will be used for each task when posted onto the
time schedule.
Figure 5-9. Resource assignment posted on schedule.




Figure 5-10. Percentage committed posted on schedule, for Marie S.




Figure 5-11. Calculation of individual effort allocation for Marie S.
Let™s go back to Marie. The last column in the diagram Figure 5-12 shows Marie™s individual effort allocation
for the tasks she will be working on. Next let™s post these allocations to the schedule. You try. In Figure 5-13,
each team member™s individual effort allocations are posted above their corresponding task in the diagram.
Post Marie™s allocations above the tasks on which she will be working. Then for each of the major time
periods blocked out in the grid below the time schedule, write down Marie™s total individual effort allocation.
When you have completed these two steps, compare your answers with those shown in Figure 5-14.
As you can see, Marie will be working a total of .10 (or 10 percent of her time) during Month 1; .30 during
Months 1-3.5; .85 from Months 3.5-5; 1.18 during both time periods in Month 5; .18 from Month 6 to 7.5; 0
from 7.5-8.5; .33 from 8.5-9.5; and 1.33 during the last half-month of the project. The histogram in Figure
5-15 provides a picture of how Marie™s individual effort allocation is used over the life cycle of the project. (A
histogram is a graphic representation of how work effort changes over time during the project.) We have
graphed Marie™s effort allocation according to the vertical axis, designated FTE (full time equivalency). In
other words, 1.00 FTE is equal to forty hours of work. Anything above this marker is considered overtime;
anything below might be considered underutilization. Marie obviously is working overtime during Month 5
and the last half of Month 9.
Figures 5-16, 5-17, and 5-18 present the same resource analysis for the total effort allocation of the project
team. Later in the chapter, we will consider how to balance or level individual and team allocations.

Key Business Applications
Two business decisions often need to be made when applying planning techniques: making adjustments to the
schedule in order to meet mandated target dates and leveling or smoothing out overloaded resources.

Meeting Mandated Target Dates
Imagine that you and your team have produced a schedule. But then”for some legitimate or whimsical
reason”the client or senior management requires that the project be completed more quickly. What do you
do now?
The original duration of the project was determined by isolating the longest series (or path) of activities”the
critical path. Therefore, it is the critical path activities that must be shortened. This is commonly called
critical path compression. By compressing some activities on the critical path, you can shorten the duration
of the project. The major technique of critical path compression is to break a critical path activity into
overlapping tasks, a technique sometimes called fast tracking the project. There are five alternatives for fast
tracking:




Figure 5-12. Calculation of effort allocation for Marie S.
Figure 5-13. Calculation of effort allocation for Marie S.
1. Decompose the work even further. Break the critical path activity into subtasks, which are
scheduled, to the greatest extent possible, in parallel. The more subtasks that can be scheduled in
parallel, the faster the activity can be completed.
2. Alter the finish-to-start relationships. The relationships we have discussed so far have been
finish-to-start relationships; that is, one task cannot start until its predecessor task has been completely
finished. There are two types of finish-to-start precedence relationships: mandatory and judgmental. A
mandatory finish-to-start relationship cannot be changed without violating a law, regulation, or
corporate policy; therefore, it cannot be altered through negotiation. Even if the project schedule is
unacceptable to the client, mandatory finish-to-start relationships must be preserved. In our experience,
though, fewer than half of all finish-to-start relationships are mandatory. (The percentage tends to vary
from industry to industry; safety-related nuclear industry projects have a higher percentage of
mandatory relationships than almost any other industry.)




Figure 5-14. Calculation of effort allocation for Marie S.
A judgmental finish-to-start relationship is one in which the task owner of the successor task sees a risk in
overlapping the tasks. The finish-to-start relationship is a result of the team member™s believing that it is not
prudent to overlap the two tasks in question. This is a statement of professional judgment on the part of the
person responsible for the successor task. All other things being equal, it is wise for you to respect this
judgment of the task leader and to leave the finish-to-start relationship alone. However, when altering one or
more of the judgmental finish-to-start relationships makes the difference between undertaking or shelving the
project, it may be appropriate to negotiate revisions to these judgmental relationships.


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You and the task owner must remember that altering the judgmental finish-to-start relationship represents an
Title
additional risk, which depends on the specifics of the tasks being overlapped. There is always a risk when
such action is taken; although the period of performance for the project may be shortened and the cost may
not increase, the decision has some potential to backfire, causing both a schedule delay and increased costs.

-----------




Figure 5-15. Individual resource loading histogram for Marie S.




Figure 5-16. Team resource availability.




Figure 5-17. Team resource availability and scheduling.




Figure 5-18. Team effort loading histogram.

Relationships that are judgmental can be reevaluated as partial relationships. There are several approaches:
1. Establish percentage dependencies in which the critical path activity requires less than 100 percent
of its immediate predecessor. For example, perhaps only 20 percent of the entire design process needs
to be finished before development can be started.
2. Try start-to-start relationships with a lag. The critical path activity starts at the same time as its
predecessor, with a predetermined lag or delay time. For example, development can start one month
after design has started.
3. Choose a finish-to-finish relationship with a lead. The critical path activity must be completed at a
specified number of time units before its successor is completed. For example, the design work must be
completed two weeks before the development is scheduled to be completed.
4. Reevaluate and break dependencies since dependencies indicate that one activity must be completed
before another can begin. For example, the design of the product is not going to begin until funding is
obtained. But what if there is a marketing window to be met? It may be wise to break the conservative
relationship of receiving funding before the start of design, starting the design at the same time that the
acquisition of funding begins. This option may put the project at a higher risk, but if the higher risk is
agreed to, the alternative is viable.
Implementation of any of these alternatives assumes that there are enough resources available to work on all
of the subtasks that would be going on in parallel.
3. Assign more resources. There are several ways to assign more resources to the critical work
activities. First, try to work within the resources already assigned to the project. Perhaps a project
member is not working on the critical path and could give the project more time.
You could analyze the noncritical paths to determine if any resource with the correct skill mix is available to
be reassigned to other, parallel critical path activities, thus shortening the duration of the critical path
activities. Remember that removing a resource from a non-critical path activity will lengthen the duration of
that activity and that the noncritical path may turn into the critical path.
If there are an inadequate number of people assigned to the project, recruit from within the organization or
from outside contractors. Continually reevaluate the extra dollars that these resources will cost the project.
Keep in mind, however, that the resources must have the appropriate skills required by the critical path
activities. Do not assign resources to an activity based upon their time availability alone.
4. Remove an activity from the critical path. This option certainly will shorten the critical path, but it
may also reduce the functionality of the end product or increase the risk of failure on the project.
5. Expedite a critical path activity. The duration of a critical path activity may be shortened by making
it more efficient or finding a faster way to get the job done. This may mean spending more money.
However, the additional cost may have a positive return on investment by getting the project done
sooner, with the benefits accruing at an earlier date. This does not mean slicing days off the estimate
with no thought of the reality of the new estimate.
Too often when the project planner is given a mandated completion date shorter than the derived critical path
time estimates, additional dollars and/or resources are requested as a knee-jerk reaction. Through the use of
some of these techniques, responding to a constrained time frame may be accomplished without spending
additional resources or dollars.

Resource Leveling
Leveling Within the Project
If there are resources that have been overloaded after they have been allocated, how do you level (or smooth)
them out?
When supply falls short of demand, there are a number of approaches to leveling:
• Tasks can be shifted or extended within their float. This may eliminate unacceptable peaks without
altering the cost of any part of the workload.
• Use overtime to meet the demand during the period of forecasted overutilization.
• Ask the team members to exert extra effort. Compensation or time off can be offered to staff
members working a number of hours substantially in excess of the norm.
• Augment the resource pool through the use of temporary help. (This is often not feasible, however,
due to the need to provide work space, tools, and facilities to the temporary workers.)
• Contract out a portion of the workload. This relieves the organization of the burden of providing
space, tools, and facilities, but it also potentially increases the cost of achieving the organization™s
objectives.
• Increase the size of the resource pool permanently. If the forecast of supply versus demand yields
multiple periods of overutilization well into the future, adding staff to the resource pool may be the
most effective approach to manage the workload.
• Select a portion of the workload to be delayed beyond its approved completion date in order to
eliminate the peaks in the demand for the resource. Performing this alternative, referred to as
resource-constrained scheduling, requires an understanding of the relative priorities of each component
of the project and nonproject workload of the resource pool.
When supply exceeds demand, some of these same approaches can be used to level demand:
• Tasks can be moved within their float to take advantage of the resource pool™s available time.
• Overtime can be eliminated, and any temporary help being employed by the organization can be
replaced with permanent staff.
• Management can consider reducing the size of the resource pool selectively if the forecast shows a
prolonged period of oversupply.
• Low-priority work can be moved up in the organization™s schedule to take advantage of the
availability of the resources.
There are two other possibilities that represent unique opportunities during oversupply:
• Use these periods to develop new methods for the cost-effective performance of the work of the
resource pool.
• Cross-train staff during these periods so that they can be allocated in the future to components of the
workload they are not now qualified to perform.


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Project Management
by Joan Knudson and Ira Bitz
AMACOM Books
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Leveling by the Functional Manager
Title

Resource leveling on the part of the functional manager is a key element in efficient and cost-effective
management of the organization™s project workload. In order to perform resource leveling well, the functional
managers must understand the objectives of the organization, be familiar with the relative priority of each
----------- component of the workload, and obtain the cooperation of project managers.
Problems of oversupply of resources and assets (underutilization) or excess demand for resources and assets
(overutilization) are solved in the same manner. The following approaches, all of which require negotiation
between the functional and the project managers, are helpful:
Solving Resource Utilization Problems
• Move tasks on any project, within float, to level demand.
• Alter the time-cost-resource mix to level the demand. (This may alter the cost of the task.)
• Use overtime to accommodate demand. (This may alter the cost of the task.)
• Use temporary help, under the supervision of the functional unit, to address demand peaks. (This
may alter the cost of the task.)
• Rent equipment to address peak demands. (This may alter the cost of the task.)
• Contract out a portion of the workload to address peak demands. (This may alter the cost of the
task.)
• Seek management permission to acquire additional resources or assets to address peak demands.

If the functional manager cannot resolve the problem with these techniques, the final alternative is to identify
the lowest-priority project that is contributing to the unacceptable peak demand and delay it. This may require
the approval of management and several group business managers, since it will alter an approved completion
date. Plan revisions that must be made to resolve resource and asset demand problems must be forwarded to
the project managers, so that they can produce updated plans. This step cannot be completed unless senior
management establishes priorities for project and nonproject workloads. Senior management tends to make
such priority decisions as they are required and to communicate them effectively. It is counterproductive to
level demand for resources over a long time frame. The only constant in project management is change, and it
is expected that demand for resources in future periods will change.
Project Budget
The purpose of a project budget is to take each category of one-time developmental expenses (budgeted) and
allocate it across the duration of the project, indicating when the dollars are committed or booked to be spent.
This step has two parts:
1. Allocate budget onto a cost spread sheet. Based on the resource loading, the resource (labor) dollars
required may be determined over time. Other categories of expenses may be spread across time and
summed to determine a complete budget. Figure 5-19 shows a periodic cost spread sheet in which the
budget is spread out on a month-to-month basis over the nine-month cycle of the project. Figure 5-20
shows a cumulative cost spread sheet in which the budget is spread out to date by period. Remember
that the cost spread sheet is cumulative period to date. Validate the cost spread sheet, remembering that
expenses can never decrease.
2. Plot the budget expenditures on a cost line graph in order to translate the cost spread sheet into a
graphic representation. Draw the grid with “Units of Time” along the top and “Costs” along the left
side of the grid, and plot the committed expenses in a line graph format (Figure 5-21). Create an
individual line graph for each category of expenses as well. Validate the cost line graph by checking
that it looks like an elongated capital letter S, or a straight diagonal, which is possible, but unlikely.

Risk Assessment and Contingency Planning
Risk is a certainty in project planning; managing it can be the pivotal factor in successful project
management. A sound approach to the management of risk requires an additional effort in planning but can
achieve a worthwhile return on investment. Risk analysis is a what-if exercise to identify areas of concern.
Contingency planning may mean making backup plans or more conservative scheduling of tasks and
resources.
One way to introduce the subject of risk assessment is to ask the project team members to describe the
unexpected things that have gone wrong during other projects on which they have worked. Perhaps
management introduced new priorities; the best people suddenly were not available; the budget was reduced;
another group or vendor was late; another group or vendor was over budget; another group or vendor made
something that didn™t work; or unforeseen technical problems appeared.
Isolate risk in the areas of the schedule (to include factors that may cause delays), resources (to include factors
that may threaten availability), finances (to include factors that may threaten the project budget), and scope (to
include factors that make the completion of the end product uncertain).



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