Understanding the constraint triangle in project management

Introduction

The critical success/failure factors vary from project to project. As a result, there is no universal definition of project success and project failure. It is widely suggested that the project success can be generally measured based on traditional norms of scope, budget, schedule as well as quality, satisfaction, and intended outcomes.

Delivering a successful product, service or outcome depends on whether it is delivered on time, cost, and as per the expectations or not. The expectations or what we call project requirements of a client are expected to be met by the project management team with an “application of knowledge, skills, tools, and techniques to project activities” (PMBOK 2017).

In other words, the project management team addresses the client's needs and prepares a project scope which is “work performed to deliver a product, service, or result with the specified features and functions” (PMBOK 2017). The work to be performed as part of the project scope has a definite deadline (time) and adequate funding (cost). In the lexicon of project management studies, the deadline and funding are termed as schedule and budget respectively.

While the project scope decides how much money is kept aside to budget the project, the schedule determines the duration required to deliver the project on time without exceeding the budget. Project scope, schedule, and budget are referred to as direct project objectives or triple constraints in the subject matter of project management studies (Meredith and Mantel 2018).

Example

The dynamic within which the triple constraints operate in project management is described by Haugan (2010) in his book?Project Management Fundamentals – Key Concepts and Methodology. He draws our attention to the fact that 1) if the schedule changes and the scope does not change, then the project manager has to alter the budget which may impact the project as a whole; and 2) if the scope is poorly defined and the subsequent changes are not made, the budgetary allocation of resources and planned schedule fails.?

For example, Tokyo Disneyland Park started its construction on 3 December 1980 and took two years and four months to complete the work and finally opened on 25 April 1983. The project scope included the development of an entertainment park and operationalizing the park with adequate staffing.

But, what was estimated to be a 100 billion yen project soared up to 180 billion yen (OLC Group 2020). In addition to that, although the construction was completed in 1882, the Disney staff failed to hire about 3000 part-time Cast Members as the need to develop an efficient transport system for commuting from Tokyo to the Maihama area was overlooked. It was after a six-month delay that the hiring process finally got enough cast members through its Tokyo Disneyland Employment Center, intensive training, preview, and mock demonstrations to run various events and programs at the park.

From the triple constraint perspective, a lack of clarity on scope led to an increase in budget and schedule. The project could have met a scope creep, but by pumping money the project was saved. As illustrated in Diagram 1, the prior project and changes in it are highlighted.

Criticism

The inter-relationship and trade-offs emanating from scarcity between triple constraints that influence project success and performance are subject to the project manager’s scrutiny. The influence of these constraints varies from project to project, but there are limitations on the utility of the concept of triple constraint in project management. Critics of the triple constraint concept argue that it does not take into consideration qualitative factors such as strategy, sustainability, and safety (Toor & Ogunlana 2010) in the assessment of performance evaluation criteria.

In addition to sustainability, Tinoco, Sato, and Hasan (2006) add responsibility and accountability to measure the performance of the project while handling mega projects. Besides these critics, Andersen (2016) compares the task perspective (the triple constraint) with an operational perspective which “implies that the project manager's focus is to support value creation in the receiving organization”.

In the same vein, Shenhar and Dvir (2007) propose an adaptive project management thinking that stresses more on “business results and meeting multiple performance criteria” instead of a mere success of achieving the project with scope, budget, and schedule considerations.

Hence, to pay attention to the trade-offs between constraints and at the same time, the criticism that the triple constraint has drawn in recent years' project managers are advised to determine which model in the development life cycle that constitutes the project life cycle matches with project scope, budget, and schedule. These models can be either “predictive, iterative, incremental, adaptive, or a hybrid” (PMBOK 2017). These models can help to bring flexibility in the project life cycle by tailoring the constraints thereby achieving excellent performance targets.

?Conclusion

The evaluation of project success or failure cannot be judged purely based on scope, budget, and schedule, but it does inform us about the constraints that might have occurred in the project management if the projects tend to fail. It forms the foundation on which other factors such as quality, satisfaction, and outcomes of the project can be measured. Adequately defined project scope, cost, and planning assist project success coupled with the right balance of leadership and management skills instilled in the project management team. To encompass these skills, it is essential that a project manager update, communicate, and widen her/his knowledge horizons, work with stakeholders, and amend/avoid the mistakes in the project life cycle.

References

Andersen, ES 2016, ‘Do project managers have different perspectives on project management?’, International Journal of Project Management, vol. 34, no. 1, pp. 58–65.

Haugan, GT 2010, Project Management Fundamentals – Key Concepts and Methodology, Berrett-Koehler Publishers, Virginia, viewed on 03 March 2020, <https://books.google.com.au/books/about/Project_Management_Fundamentals.html?id=4hhFDwAAQBAJ&redir_esc=y>.

Meredith, JR & Mantel, S 2018,?Project management: A managerial Approach, 10th edn, Wiley.

OLC Group 2020, Opening of Tokyo Disneyland, Oriental Land Company Limited, viewed 02 March 2020,<https://www.olc.co.jp/en/company/history/history03.html>.

PMBOK 2017, A Guide to the Project Management Body of Knowledge, 6th edn, Project Management Institute, Inc.

Shenhar, AJ & Dvir, D 2007, Reinventing project management: the diamond approach to successful growth and innovation, Boston, MA, Harvard Business School Press, viewed 03 March 2020, <https://books.google.com.au/books?hl=en&lr=&id=f5_BAgAAQBAJ&oi=fnd&pg=PR7&dq=shenhar+dvir&ots=b0p8y-17i8&sig=TYPG8YnknaTlkOfhzGRmLUQmnEM&redir_esc=y#v=onepage&q=shenhar%20dvir&f=fals>.

Tinoco, RA, Sato, CEY & Hasan, R 2016, ‘Responsible Project Management: beyond the triple constraints’, The Journal of Modern Project Management, vol. 4, no. 1, pp. 81-93.

Toor S & Ogunlana, SO 2010, ‘Beyond the ‘iron triangle’: Stakeholder perception of key performance indicators (KPIs) for large-scale public sector development projects’, International Journal of Project Management, vol. 28, no. 1, pp. 228–236.

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