Which of the triple constraints (schedule, scope, budget) is most difficult to attain?

There are two outline points: the client expectations and the company strategy.

The Project Management Triangle (called also Triple Constraint or the Iron Triangle) is a model of the constraints of project management. It is a graphic aid where the three attributes show on the corners of the triangle to show opposition. It is useful to help with intentionally choosing project biases, or analyzing the goals of a project. It is used to illustrate that project management success is measured by the project team's ability to manage the project, so that the expected results are produced while managing time and cost (Wikipedia). The thought-provoking question is: which of the triple constraints (schedule, scope, and budget) is most difficult to attain?

The nature of each project drives the relative priority of its constraints - a regulatory compliance project may be focused on minimal scope within a fixed schedule and flexibility on cost; while a discretionary project without external commitments might be most challenged on schedule. The real value-added, experienced Program Manager is to keep a proper balance between the 3 constraints (schedule, scope, budget). 

There are two outline points: the client expectations and the company strategy. The managers have to balance between those points and find the way to conciliate the objectives. It's not an easy task but if the managers have a total support of his or her hierarchy, the development of the approach should be done logically to uncover a two-part problem: 
(1) A blatant optimism bias that plagued the task duration and effort estimates. 
(2) Ambiguous requirements that caused a lot of rework very late in the quality testing cycle. 

Agile methodology focuses on iterative delivery and continuous improvement. Nowadays the speed of change is accelerated, everyone is hard pressed on delays, and favoring a quick delivery on a good enough scope, that PM can iteratively improve. It also gives time for the business to adjust its requirements that are not always well defined in details and subject to evolution with market trends. 

There’re all types of challenges on the SCOPE: Scope is typically always the area where there can be many issues with interpretation, decomposition, assumptions, and lack of continuity and understanding between the stakeholders. As we all appreciate there are many ways to deal with these types of challenges, it seems to always turn out to be the most difficult constraint to tackle and manage throughout the life cycle.

3”D” sessions to clarify critical constraint. It always seems to be the trade space based on stakeholder ease of suggesting Budget and Time are fixed, with no desire to give up Quality. A way to deal with this is to have many 3D sessions (Discuss, Debate, and Decide) with the key stakeholders in the project. The key stakeholders are the customer for whom you are delivering the project. It may not be the "user" because it can be the "buyer" who speaks for the user. You must be clear on what the "user" needs are as well. Especially if the "buyer" is not fully engaged with the "user". It can be tricky to manage, but it's crucial to do it. Data is King when you’re in the 3D session.

Hence, depending on the situation, the customer will be more driven by cost/time or scope. The tradeoff can be made through in-depth understanding of project nature, ultimate business strategy and goals, project management methodology or disciplines, and have 3D sessions to decide your key constraint.

Posted in: Chicken & Egg Puzzles,Project Management