Part of the education process for your client might involve the concept of the "triple constraint." At the end of the up-front planning process, you should have created an estimate of the work that ... If you don’t have a formal agreement on these factors to begin with, then the triple constraint concept does not work.
articles.techrepublic.com.com/5100-10878_11-5925682.htm... articles.techrepublic.com.com/5100-10878_11-5925682.html
The closest reference I could find in the PMBOK Guide - 4th Edition to the triple constraints concept was under Risk -  section 11.3, page 289. Although the triple constraints model may not be in the PMBOK, I believe it to be a Best Practice and a great tool ... Maybe that is why the triple constraint is not in the PMBOK.
projectmanagementblog.globalknowledge.com/2009/06/01/tr... projectmanagementblog.globalknowledge.com/2009/06/01/triple-constraints-model/
A concept that acknowledges that money changes value over a period of time; that a sum of money today is worth more ... Triple Constraint; The term used to describe the three key project objectives that must be simultaneously accomplished, namely, the performance specification, the time schedule, and the monetary budget.
www.projectauditors.com/Dictionary/T.html
www.pdma.org/bookstore/books/success_project_review.htm... www.pdma.org/bookstore/books/success_project_review.html
The specific tradeoffs may vary from project to project, but they always return to the concept of the triple constraint – technical requirements, schedule, and cost. ... Exhibit 2-1: The Triple Constraint Concept...
www.ceh.nasa.gov/webhelpfiles/Life_Cycle_Management_and... www.ceh.nasa.gov/webhelpfiles/Life_Cycle_Management_and_the_Role_Cost_Plays.htm
Another Perspective on the Triple Constraint; The triple constraint, where project cost, project quality, and project time (or project schedule) pose tradeoffs, is a very common project management concept.
pmcrunch.com/project_management_process/tolerance-and-t... pmcrunch.com/project_management_process/tolerance-and-the-triple-constraint/
Project Example: The Triple Constraint in Project Management; By Jessica Popp ... For now, let’s focus on the triple constraint and how its components can be used as levers. Rarely in a project will you see a set of triple constraints that can be met as-is. Often one of the constraints is seemingly out of line...
www.pmhut.com/project-example-the-triple-constraint-in-... www.pmhut.com/project-example-the-triple-constraint-in-project-management
The Triple Constraint is a pretty fundamental concept to the theory of project management. Imagine, if you will, a triangle with Time in one corner, Cost in another and Quality in the last (I will add a diagram later if I can be bothered).
projectcentric.co.uk/how_to_manage_a_camel/projectmanag... projectcentric.co.uk/how_to_manage_a_camel/projectmanagement/guest-pm-blogger-whats-wrong-with-the-triple-constraint/
MayPDF (PDF File)
Anyone can understand the triple constraint concept; however, managing the triple constraint successfully is the hard part. It’s similar to a diet — the concept of a diet is easy: If you consume fewer calories than you burn, you will lose weight.
www.esi-intl.com/Public/publications/Horizonspdfs/horiz... www.esi-intl.com/Public/publications/Horizonspdfs/horizons0704.pdf
As the project manager, it's your job to educate your sponsor and other key stakeholders regarding the triple constraint concept and to manage them effectively. Anyone can understand the triple constraint concept;
www.esi-intl.com/Public/publications/HTML/0704triplecon... www.esi-intl.com/Public/publications/HTML/0704tripleconstraints.asp