The Triple Constraint.
One of the fundamental concepts of all project management is the idea of the triple constraint. Since basic project management revolves around this concept, and earn value relies on using the triple constraint I’ll describe it here. Graphically the triple constraint can be viewed as a triangle with each corner representing one of the constraints.
Figure 1 the Triple Constraint
A “balanced” project will have all three corners equally tugging at the center. The area inside of the triangle can be thought of as a representation of all that the project encompasis. All projects are based on an agreed to level of scope, a time to do the work, and of course a budget allocated to do the work. These three items can be defined simply as scope (technical), budget (cost), and schedule (time).
The scope is defined by the type of work being performed such as a service or the creation of goods. The cost is the monetary value placed on the scope. Some work is defined by the amount of hours it takes to do the work; however an hourly rate multiplied by the amount of hours required to do the work will describe the cost of the effort.
Time is measured generally in months, but sometimes can be measured in weeks. When planning a project all three constraints are taken into consideration since they are tied together. If the project team and stakeholders do a good job of defining the work, time, and budget necessary to do the work, greater project execution control is maintained. The triangle will be equal and balanced. Project managers should employ lessons learned and history from earlier projects to help them arrive at the cost to do the work. In a similar way the same approach can be used to determine the time it takes to execute the project.
When dealing with new technology and work which has never been performed the three constraints tug at each other unevenly. Theoretically all the sides and angles of the triple constraint start equally at the onset of the project. However as the project progresses, each constraint is challenged due to risks introduced uncertainties, plus the introduction of variables and variances.
The PM utilizing Earned Value Management (EVM) has a way to measure how well the team is performing to cost and schedule. EVM requires teams to become more disciplined at planning a project, and utilizing tools which give a means to control the triple constraint.
In order for the PM to go beyond the traditional performance measurement method of looking at actuals accrued and comparing them to the budgeted work, the PM will need the following project tools, structures, and controls.
- A project plan
- An organization structure
- A responsibility assignment matrix
- A work breakdown structure
- Control Accounts
- Measurement and reporting vehicles
- Risk Assessments
- Variance Analysis
- Monthly reporting documentation
- Forecasting tools
- Project Controls
Ultimately the PM will use these tools in various ways with earned value management as the centerpiece to manage the triple constraint and the project more efficiently. The PM will be able to communicate important developments to the team, coach the team towards success, and appraise the customer on the health of the project and the team’s ability to meet customer expectations.
I’ll continue posting more insight beyond the traditional approach of performance measurement. Sign up as a follower to my blog to receive alerts via WordPress when the next post is published. Thanks for reading and tally ho!