Chapter 8 Flashcards
Types of Project Constraints
Technical or Logic Constraints
Physical Constraints
Resource Constraints
Technical or Logic Constraints
Constraints related to the networked sequence in which project activities must occur.
Physical Constraints
Activities that cannot occur in parallel or are affected by contractual or environmental conditions.
Resource Constraints
The absence, shortage, or unique interrelationship and interaction characteristics of resources that require a particular sequencing of project activities
Kinds of Resource Constraints - people, materials, equipment
Classification of a Scheduling Problem
Classification of Problem
Using a priority matrix will help determine if the project is time or resource constrained.
Time-Constrained Project
Must be completed by an imposed date.
Time is fixed, resources are flexible: additional resources are required to ensure project meets schedule.
Resource-Constrained Project
Is one in which the level of resources available cannot be exceeded.
Resources are fixed, time is flexible: inadequate resources will delay the project.
Resource Solutions
Resource Smoothing (or Leveling) Resource-Constrained Scheduling
Resource-Constrained Scheduling
The duration of a project may be increased by delaying the late start of some of its activities if resources are not adequate to meet peak demands.
Resource Smoothing (or Leveling)
Involves attempting to even out varying demands on resources by using slack (delaying noncritical activities) to manage resource utilization when resources are adequate over the life of the project.
Resource Allocation Methods
Limiting Assumptions
Risk Assumptions
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.
Limiting Assumptions
Splitting activities is not allowed—once an activity is start, it is carried to completion.
Level of resources used for an activity cannot be changed.
Resource Demand Leveling Techniques for Time-Constrained Projects
Advantages
Peak resource demands are reduced.
Resources over the life of the project are reduced.
Fluctuation in resource demand is minimized.
Disadvantages
Loss of flexibility occurs from reducing slack.
Increases in the criticality of all activities.
Resource-Constrained Projects (Info)
Resources are limited in quantity or availability.
Activities are scheduled using heuristics (rules-of-thumb) that focus on:
Minimum slack
Smallest (least) duration
Lowest activity identification number
The parallel method is used to apply heuristics
An iterative process starting at the first time period of the project and scheduling period-by-period the start of any activities using the three priority rules.
Splitting
A scheduling technique use to get a better project schedule and/or increase resource utilization.
Involves interrupting work on an activity to employ the resource on another activity, then returning the resource to finish the interrupted work.
A major reason why projects fail to meet schedule.
Resources and Priorities
Project network times are not a schedule until resources have been assigned.
The implicit assumption is that resources will be available in the required amounts when needed.
Adding new projects requires making realistic judgments of resource availability and project durations.
Cost estimates are not a budget until they have been time-phased.