Trade-Off Between Cost and Schedule

RT-214 Topic Summary
RT 214


Projects must meet budget, schedule, safety, and quality goals to be regarded as a success. Many decisions are made that influence a project’s outcome. Today, owners are often faced with deciding between a project execution strategy that emphasizes either cost or schedule. Such decisions are made throughout the life cycle of the project.

Through surveys of CII member organizations and case studies, the research team identified 23 techniques that consistently influence project success through optimization of cost and schedule. The team then created the Cost-Schedule Trade-Off Tool (CSTT) to assist in selecting the optimum group of techniques to achieve a specific cost-schedule trade-off. The tool identifies and quantifies cost/schedule trade-offs and can be used to prioritize techniques based on their effectiveness during various project phases. The intent is to select appropriate execution techniques that may be incorporated into projects to achieve the desired balance between cost and schedule.

The techniques recommended by the tool are not unique, but are routinely used in successful project management. In fact, many of the techniques are CII Best Practices. The key, however, is that the CSTT helps the user in knowing the specific techniques to employ at each stage of the project. Project teams can then use these techniques in a more timely fashion to increase the likelihood of project success, particularly in an era when trade-offs are continually being made to favor cost over schedule. 

Key Findings and Implementation Tools

1 : Cost/Schedule Drivers and Execution Techniques

This research identified six major drivers governing cost/schedule trade-offs and 23 techniques of most value to project teams. A sampling of the drivers and techniques are shown below. Refer to the Research Summary for the complete lists. (RS214-1, p. 22)

Representative Major Drivers
  1. Executive sponsorship
  2. Owner’s need
  3. Owner’s commitment
  4. Legislative/environmental
A Sampling of the 23 Execution Techniques
  1. Alignment
  2. Effective communication
  3. Empowerment
  4. Team building
  5. Change management system
  6. Constructability
  7. Measuring design effectiveness vs. project objectives
  8. Risk management system
  9. Value engineering
  10. Cost control systems
Reference: (RS214-1)

2 : Trade-off Barriers

This research identified the most significant barriers to the trade-off between cost and schedule (RS214-1, p. 4):

  • Unclear project objectives or business definition
  • Lack of alignment with project objectives
  • Poor planning
  • Scope changes
  • Poor decision making
  • Turnaround/outage schedule
  • Lack of project team alignment
Reference: (RS214-1)

3 : Implementation Tool #1

IR214-2, Cost/Schedule Trade-Off Tool (CSTT)

CSTT is an Excel-based tool to evaluate the degree of trade-offs and to assist in identifying techniques to optimize cost and schedule.


Operation of the CSTT

The CSTT analyzes the importance of project drivers and quantifies trade-offs between cost and schedule based on these drivers. It then ranks the techniques based on their effectiveness and lists the applicable techniques for each individual project phase, as well as the project as a whole. A flowchart of the operation of the CSTT is shown below.


Driver Analysis

On the first input screen, users are asked to weigh the top six project drivers on a scale of 1-10 with respect to their importance in the overall project. In the second section, the drivers are rated again with respect to the importance of cost or schedule reduction from the standpoint of each of the drivers. On the second input screen the user is asked to distribute project cost and schedule duration among the five phases:

  • Pre-project planning
  • Design
  • Materials
  • Construction
  • Startup

CSTT Output

The initial output screen provides a graphical representation of the cost/schedule trade-off, identifying whether the project should be handled as “cost-driven” or “schedule-driven,” as well as a listing of the top techniques identified for the overall project and those for each project phase.
Reference: (IR214-2)

Key Performance Indicators

Improved cost, Improved schedule

Research Publications

Cost/Schedule Trade-Off Tool - IR214-2

Publication Date: 01/2007 Type: Implementation Resource Pages: 0 Status: Tool

Trade-Off between Cost and Schedule - RS214-1

Publication Date: 01/2007 Type: Research Summary Pages: 27 Status: Supporting Product

Trade-Off Between Cost and Schedule - RR214-11

Publication Date: 12/2006 Type: Research Report Pages: 170 Status: Reference

Presentations from CII Events

Plenary Session - Trade-Off Between Cost and Schedule

Publication Date: 06/2006 Presenter: Number of Slides: 18 Event Code: AC06

Implementation Session - Trade-Off Between Cost and Schedule

Publication Date: 06/2006 Presenter: Number of Slides: 33 Event Code: AC06

Session - Investigation of Trade-Offs Between Cost and Schedule

Publication Date: Presenter: Number of Slides: 30 Event Code: PIW905

Session - Trade Off Between Cost & Schedule

Publication Date: Presenter: Number of Slides: 62 Event Code: PIW1009