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CH8: Scheduling Resources and Costs - Coggle Diagram
CH8: Scheduling Resources and Costs
Learning Objectives
08-01 Understand the differences between
time-constrained
and
resource-constrained
schedules.
08-02 Identify different types of
resource constraints.
08-03 Describe how the
smoothing approach
is used on
time-constrained projects
.
08-04 Describe how the
leveling approach
is used for
resource-constrained projects
.
08-05 Understand how project management software creates
resource-constrained schedules
.
08-06 Understand when and why
splitting tasks
should be avoided.
08-07 Identify general guidelines for
assigning people to specific tasks
.
08-08 Identify common problems with
multiproject resource scheduling
.
08-09 Explain why a
time-phased budget baseline
is needed.
08-10 Create a
time-phased project budget baseline
.
8.3
Classification of a Scheduling Problem
Time-Constrained Project
Must be completed by an
imposed date
.
Time (project duration) is fixed and
resources are flexible
. If required, resources can be added to ensure the project is completed by a specific date.
Resource-Constrained Project
Assumes the level of
resources available cannot be exceeded
.
Resources are fixed and
time is flexible
. If the resources are inadequate, it will be
acceptable to delay the project
.
Consult a project priority matrix to determine if the project is time- or resource- constrained.
8.5 Computer Demonstration of Resource-Constrained Scheduling
EMR Project
The development of a
hand-held electronic medical reference guide
to be used by emergency medical technicians and paramedics
Resource Problem
Only
eight
design engineers can be assigned to the project due to the shortage of design engineers and commitments to other projects.
The
peak demand is 21
design engineers
EMR Project Network View Schedule before Resources Leveled
EMR Project before Resources Added 實例
EMR Project—Time-Constrained Resource Usage View, January 15-23 實例
Resource Loading Chart for EMR Project, January 15-23
EMR Project Network View Schedule after Resources Leveled
EMR Project Resources Leveled 實例
The Impacts of Resource-Constrained Scheduling
Reduces slack;
reduce flexibility
Increases
the number of
critical and near-critical
activities
Increases
scheduling complexity
because resource constraints are added to technical constraints
May make the traditional critical path no longer meaningful
Can
break the sequence
and leave the network with a set of
disjointed critical activities
May cause
parallel
activities to
become sequential
Can change activities from
critical to noncritical
8.6
Splitting Activities
Splitting Tasks
Is a scheduling technique used to get a better project schedule and/or to
increase resource utilization
.
Involves
interrupting the work and sending the resource to another activity
for a period of time and then having the resource resume work on the original activity.
Can be useful if the work involved does
not include large start-up or shut-down costs
.
Is considered a
major reason why projects fail to meet schedule
.
Splitting Activities 實例
8.7
Benefits
of Scheduling Resources
Leaves time for considering reasonable alternatives
Cost-time tradeoffs
Changes in priorities
Provides the information needed to
prepare time-phased work package budgets with dates
To gauge the impact of
unforeseen events
To assess how much
flexibility
over certain resources
8.8 Assigning Project Work
Reasons why we should
not
always
assign the best people the most difficult tasks
Best people
: resent to the fact that they are always given the toughest assignments
Less experienced
participants: resent to the fact that they are never given the opportunity to expand their skill/knowledge base
Factors to be considered in deciding who should work together
Minimize unnecessary tension; complement each other
Experience
: veterans team up with new hires
Future needs
: have people work together early on so that they can become familiar with each other
8.9 Multiproject Resource Schedules
Problems in a multiproject environment
1. Overall schedule slippage
Shared resources causes a
ripple effect
—delays in one project create delays for other projects.
2. Inefficient resource utilization
Different schedules and requirements by multiple projects create the
peaks and valleys in overall resource demands
.
3. Resource bottlenecks
Shortages of critical resources
required by multiple projects cause delays and schedule extensions.
Managing Multiproject Scheduling
Create
project offices or departments
to oversee the scheduling of resources across multiple projects
Use a
project priority queuing system
—first come, first served for resources
Treat individual projects as part of one big project and adapt the scheduling heuristics to this “
mega project
”
Utilize project management
software to prioritize
resource allocation
Outsource
projects to reduce the number of projects managing internally
Hire
temporary workers
to expedite certain activities that are falling behind schedule
Contract project work during peak periods
when there are insufficient internal resources to meet the demands of all project
8.10 Using the Resource Schedule to Develop a Project Cost Baseline
Why a
Time-Phased Budget Baseline Is Needed
To determine if the project is
on, ahead, or behind schedule
and
over or under its budgeted costs
To assess how much work has been accomplished for the allocated money spent—the
project cost baseline
(planned value, PV)
Creating a
Time-Phased Budget
Assign
each work package to one responsible person or department
and deliverable
Compare
planned schedule and costs using an integrative system called earned value
Generate
cash flow statements
and
resource usage schedules
Direct Labor Budget Rollup ($000) 實例
Time-Phased Work Package Budget (labor cost only)實例
Two Time-Phased Work Packages (labor cost only) 實例
Patient Entry Project Network 實例
Patient Entry Time-Phased Work Packages Assigned實例
Project Monthly Cash Flow Statement 實例
Project Weekly Resource Usage Schedule 實例
Project Planning Process 實例
8.1 Overview of the
Resource Scheduling Problem
Resources and Priorities
Project network times are not a
schedule until resources have been assigned
.
The project priority team will
add a new project only if resources are available
.
There are always
more project proposals than there are available resources.
Cost estimates are not a budget until they have been time-phased.
Once
resource assignments have been finalized
, you are able to develop a
baseline budget schedule
for the project.
8.2
Types of Resource Constraints
The Resource Scheduling Problem
Resource Smoothing
Involves attempting to
even out varying demands on resources
by
delaying non-critical activities
(using slack) to
lower peak resource demand
and, thus,
increase resource utilization
when
resources are adequate
over the life of the project.
Resource-Constrained Scheduling
Occurs when
resources are not adequate
to meet
peak demands
. The late start of some activities
must be delayed
, and the duration of the project
may be increased
.
Types of Project Constraints
Resource Constraints
Occur when the absence, shortage, or unique interrelationship and interaction characteristics of resources require a
particular sequencing of project activities
.
Note that the
resource dependency takes priority over the technological dependency
but does not
violate the technological dependency
.
Technical or Logical Constraints
Are related to the networked
sequence
in which project activities must occur.
Types of Resources Constraints
People
Materials
Equipment
Constraint Examples 實例
8.4
Resource Allocation Methods
Limiting Assumptions
Splitting activities will not be allowed.
Splitting
refers to interrupting work on one task and assigning the resources to work on a different task for a period of time, then reassigning them to work on the original task.
Level of resources used for an activity cannot be changed.
Risk Assumptions
Activities with the
most slack pose the least risk
.
Reduction of flexibility does not increase risk.
The
nature of an activity
(easy, complex)
doesn’t increase risk
.
Time-Constrained Projects
Must be completed by an imposed date.
Focus on
resource utilization
.
Require use of
resource smoothing techniques
that balance demand for a resource.
Leveling (Smoothing) Techniques
Delay noncritical activities
by using positive slack to reduce peak demand and fill in the valleys for the resources
without delaying the entire project
.
Goals of Smoothing Resource Demand
Reduce the
peak of demand
for the resource
Reduce the
number of resources
over the life of the project
Minimize the fluctuation
in resource demand
Downside of Smoothing Resource Demand
Loss of flexibility
that occurs from reducing slack
Creates
more critical
activities and/or
near-critical activities
because of
slack reduction
Botanical Garden 實例
Resource-Constrained Projects
Resources are
limited in quantity or availability
.
Activities are scheduled using
heuristics
(rules of thumb) by following the
priority rules
:
Minimum slack
Smallest (least)
duration
Lowest
activity identification number
The
parallel method
is used to apply
heuristics
.
The parallel method is an iterative process that starts from the beginning of project time and, when the resources needed exceed the resources available, retains activities first by the priority rules.
Resource-Constrained Schedule through Period 2-3 實例
Resource-Constrained Schedule through Period 5-6 實例
