Complexity in Large Engineering and Construction Programs


By Bob Prieto

Chairman & CEO
Strategic Program Management LLC

Jupiter, Florida, USA



Increasingly, today’s large projects are complex. While recognizing this property of these projects we seemingly gloss over it, giving it much less attention than more traditional project properties.

A review of even the best developed project baseline documents will highlight efforts placed on defining and quantifying scope; delineating costs; and ascribing time to the various means & methods we will employ to deliver the project. But our focus on thorough characterization goes further assessing and addressing how risks will be provided for, tracked and managed; how safety and quality will be assured; and even how operational stage considerations will be brought forward.

But throughout our robust stage setting and subsequent management efforts we acknowledge complexity but do little to assess it, and maybe even less to manage it. While we measure changes in cost and schedule and risk profile we lack even a metric for measuring similar changes in complexity.

Complexity is not unique to the large engineering and construction projects we undertake but is a property of all large systems. How can we learn from these analogs and what strategies may help us better manage the complexity we face on these projects?

This is the “century of complexity” according to Steven Hawking, transcending the domain of experts, taking us into a realm of emergence where the multi-finality of even well-developed programs must be acknowledged and provided for. The complex may even behave chaotically, amplifying the need for timely, responsive management interventions on project paths not previously well traveled. Returning from chaos to complexity requires leadership and broad engagement of the wisdom of the team.

But our traditional organization charts and their associated position descriptions understate the management and leadership skills and attributes required to respond to the complexity these programs will inevitably face. These skills include pattern recognition, dealing with ambiguity, real time coaching and facilitation, and the ability to manage transformations not just transitions.

Nature’s complex systems offer some hints we should heed. They reward modularity and its ability to limit the effects of perturbations while at the same time recognizing that excessive modularity exposes the system negatively to the effects of even stronger perturbations. Here modules can be thought of “as a set of nodes densely connected among themselves but loosely connected to other parts”i .

But perturbations can spread even in highly modular systems with these stronger perturbations occurring along couplings not readily apparent such as what we see with constraint coupling (See Appendix 1) or other interlacing networks interacting with multiple elements of our project, potentially amplifying otherwise more manageable permutations.

Modularity in project design and management can also carry risks associated with unintended impediments of delays in information flows and decision making.

I’ve touched on organizational skills and leadership aspects to be more strongly considered when we undertake complex projects. I’ve also highlighted benefits of modularity as a project design principle but also the risks associated with unrecognized couplings. I’d like to turn now to the subject of measuring complexity. Again, here work has been done in other fields in the form of cyclomatic complexity analysis in software codes, the largest of which resemble the 50 – 100,000 activity schedules we see in large complex programs. Cyclomatic complexity is focused on control flows or the myriad of arrows we see in our project activity models and pay insufficient attention to. I have discussed this previously.ii

In a project context both module and overall program complexity need to be considered with overall program complexity considering only those connections (both apparent and otherwise) between the densely coupled modules and the rest of the program network. Application of an approach akin to cyclomatic analysis allows for a comparison of execution strategies for complex projects where today we accept but don’t seek to mitigate complexity and its threats to large complex projects.

Hawking was right, this is the “century of complexity”, but our projects do not need to be its victims.

Thoughts on Perturbations

In the previous section I looked at the relationship between complexity and modularity of “systems”.  I noted that Nature’s complex systems reward modularity and its ability to limit the effects of perturbations while at the same time recognizing that excessive modularity exposes the system negatively to the effects of even stronger perturbations.


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About the Author

Bob Prieto

Chairman & CEO
Strategic Program Management LLC
Jupiter, Florida, USA



Bob Prieto is a senior executive effective in shaping and executing business strategy and a recognized leader within the infrastructure, engineering and construction industries. Currently Bob heads his own management consulting practice, Strategic Program Management LLC.  He previously served as a senior vice president of Fluor, one of the largest engineering and construction companies in the world. He focuses on the development and delivery of large, complex projects worldwide and consults with owners across all market sectors in the development of programmatic delivery strategies. He is author of eight books including “Strategic Program Management”, “The Giga Factor: Program Management in the Engineering and Construction Industry”, “Application of Life Cycle Analysis in the Capital Assets Industry”, “Capital Efficiency: Pull All the Levers” and, most recently, “Theory of Management of Large Complex Projects” published by the Construction Management Association of America (CMAA) as well as over 600 other papers and presentations.

Bob is a non-executive director of Cardno (ASX) and an Independent Member of the Shareholder Committee of Mott MacDonald. He serves on the Millennium Challenge Corporation Advisory Board and a member of the ASCE Industry Leaders Council, National Academy of Construction, a Fellow of the Construction Management Association of America and member of several university departmental and campus advisory boards. Bob served until 2006 as a U.S. presidential appointee to the Asia Pacific Economic Cooperation (APEC) Business Advisory Council (ABAC), working with U.S. and Asia-Pacific business leaders to shape the framework for trade and economic growth.  He had previously served as both as Chairman of the Engineering and Construction Governors of the World Economic Forum and co-chair of the infrastructure task force formed after September 11th by the New York City Chamber of Commerce. Previously, he served as Chairman at Parsons Brinckerhoff (PB). 

Bob can be contacted at [email protected]

To view other works by Bob Prieto, visit his author showcase in the PM World Library at https://pmworldlibrary.net/authors/bob-prieto/