Manager's challenges--managing constraints


Today's managers face and deal with constraints far beyond the traditional project-specific triple constraints. Many “project constraints” are rooted outside of project boundaries and hence outside of managers' control, making the evaluation and management of competing demands almost an impossible task. This paper introduces a new concept, the “management constraint triangle,” and evaluates how these management constraints can potentially affect projects. The first part of this paper provides a brief overview of the current project triple constraint. Then we introduce the details of this new “management constraint triangle” concept along with scenarios and examples. Finally, we provide some recommendations on how managers can integrate this new concept into their daily managing life.


According to A Guide to the Project Management Body of Knowledge (PMBOK® Guide)—Fourth Edition, the definition of “constraint” is: “The state, quality, or sense of being restricted to a given course of action or inaction. An applicable restriction or limitation, either internal or external to a project, which will affect the performance of the project or a process” (Project Management Institute [PMI[, 2008).

Many studies and papers have been published on the interactions among project time, cost, and scope. Project management practitioners often refer to this project triple constraint, or “iron triangle,” as a framework for evaluating competing demands. However, project time, cost, and scope alone are not enough to assess, evaluate, and manage these competing demands and project constraints. In your own experience, you may have encountered certain events or challenges with your project that were beyond your control and outside the boundary of traditional project triple constraint analysis.

Current Project Triple Constraint

Project management is the application of knowledge, skills, tools, and techniques to project activities to meet project requirements. It is accomplished through the application and integration of the project management processes of Initiating, Planning, Executing, Monitoring and Controlling, and Closing. The project manager is the person responsible for accomplishing the project objectives.

Triple constraint, aka, “the iron triangle.”

Exhibit 1: Triple constraint, aka, “the iron triangle.”

Managing a project includes:

  • Identifying requirements
  • Establishing clear and achievable objectives
  • Balancing the competing demands for quality, scope, time, and cost
  • Adapting the specifications, plans, and approach to the different concerns and expectations of various stakeholders

Project managers often talk of a “triple constraint” (Exhibit 1)—project scope, time, and cost—in managing competing project requirements. Project quality is affected by balancing these three factors. High-quality projects deliver the required product, service, or result within scope, on time, and within budget. The relationship among these factors is such that if any one of the three factors changes, at least one other factor is likely to be affected. Project managers also manage projects in response to uncertainty. Project risk is an uncertain event or condition that, if it occurs, has a positive or negative effect on at least one project objective.

What is the “Management Constraint Triangle”?

Understanding the limitations of traditional project triple constraint analysis, I would like to introduce a new concept, the “management constraint triangle” (Exhibit 2). The “management constraint triangle” attempts to explore the reasons why certain events or challenges happen to a project and why they are beyond the project manager's control.

The following are the three sides of the “management constraint triangle,” with brief descriptions of sample elements of each side. Please note that the elements below are not an exhaustive list of all possible elements.

1. Resources

People – human beings, staff, and workers

System – applications, policies and standards

Tool – machine, equipments, hardware, and infrastructure

2. Financials

Revenue – income

Expense – costs or charges

Budget – itemized estimated allotment of funds

Allocation – share or portion of funds

3. Stakeholders

Sponsor – owner and decision maker

Boss – supervisor

Client – a person or group receiving the services and benefits of the project product

Customer – a person who purchases the goods or services the project produces

Management constraint triangle

Exhibit 2: Management constraint triangle

Interaction Analysis of Constraints

Exhibit 3 is a sample illustration of constraint interaction in the “management constraint triangle” model. Changing element of one group can not only potentially impact elements in the other two groups, but might also impact other members within the same group.

Management constraint triangle interaction

Exhibit 3: Management constraint triangle interaction.

Interaction Scenarios and Examples

Let's explore the interaction scenarios and examples illustrated in Exhibit 3.

Changes Impacting Elements Within a Group

Resources –

If we change the “system” used in the project, then “people” might be impacted. For example, if additional information security regulation and policy/compliance requirements were added to the project, then we might need to consider adding an information security expert to the project to ensure that new IS requirement are met.

Financials –

If we change “revenue,” then both “budget” and/or “allocation” might be impacted. For example, if the company's revenue decreased due to the current recession, then most likely many initiative budget and project allocations will be impacted.

Stakeholders –

If we change “sponsor,” then “customer” might be impacted. For example, if the sponsor of a project were to change, then the customer of the project product might also change.

Changes Impacting Elements Between Groups

Resources –

If we change the “system” used in the project, then “expense” under “Financials” might be impacted. Using the same example above, if additional information security regulation and policy/compliance requirements were added to the project, then project expense would increase with the addition of information security expert to the project.

Financials –

If we change “budget,” then both “people” and “tool” under “Resources” and both “client” and “customer” under “Stakeholders” might be impacted. For example, if, due to the current recession, we were to reduce the project budget, we would therefore need to reduce both project staff (“people”) and infrastructure (“tool”). At the same time, these changes would reduce the level of services to project client and customers.

Stakeholders –

If we change “sponsor,” then “system” under “Resources” and both “budget” and “allocation” under “Financials” might be impacted. Say, for example, that due to market demand, your project is “promoted” to be sponsored by the CEO of the company. You might need to consider adding additional functionalities (“system”) to your project and could receive more “budget” and “allocation.”

How Can You Integrate the “Management Constraint Triangle” Into Your Daily Life as a Project Manager?

In the above analysis, you may have observed that many of those constraints and their potential impacts are not within the boundary of project management. Understanding and acknowledging that “certain events” may happen to your project and that they will be out of your control will help you deal with these events when they do happen.

The conclusions of “management constraint triangle” analysis are matters of common sense when they are laid out. However, project managers are often so busy ensuring timely project completion that it's difficult for them to allocate additional time to explore “management constraint triangle” analysis. Nevertheless, it is important to understand and apply this new knowledge, as it may play a critical role in your project success.

To help integrate the “management constraint triangle” into your daily life as a project manager and help ensure success for your projects, try the following:

  • Get familiar with the “management constraint triangle” model and the potential interactions within and between groups
  • Attend your group (regional or global) and company “townhall” meetings
  • Pay attention to internal announcements for signs of change
  • Continue networking and stay up-to-date with industry best practice.


Goldratt, E. (1990). Theory of constraints. Great Barrington, MA: The North River Press.

Goldratt, E. (1997). Critical chain. Great Barrington, MA: The North River Press.

Lee, W. (2004). Project management professional: A graphical study guide. 31. Victoria, British Columbia, Canada: Trafford Publishing.

Lepore, D., & Cohen, O. (1990). Deming and Goldratt: The theory of constraints and the system of profound knowledge. Great Barrington, MA: The North River Press.

Project Management Institute. (2008). A guide to the project management body of knowledge (PMBOK®guide)—Fourth Edition. Newtown Square, PA. Author.

This material has been reproduced with the permission of the copyright owner. Unauthorized reproduction of this material is strictly prohibited. For permission to reproduce this material, please contact PMI or any listed author.

© 2010, Wei Lee
Originally published as a part of 2010 PMI Global Congress Proceedings – Melbourne, Australia



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