UCL Centre for Systems Engineering


Juan Carlos Guerrero Andrade

Thesis: Application of systems dynamics techniques to understand and improve rework across complex projects


Juan Carlos Guerrero Andrade


Dr. Michael Emes
Dr. Raul Leal

Research Theme:

Systems Dynamics, Systems Thinking, Rework in Space Projects


The size of the global space market was around £ 250 billion in 2014 [1]. As in other sectors where complex and technologically challenging projects are delivered, organizations and companies within the space sector continue to have problems regarding cost and schedule performance. For example, projects at NASA have an average of 27.6% cost overrun and 13 months delay relative to the original schedule [2]. According to Parchami [3], labour and consultant workforce rework were among the most critical factors influencing delay.

Although there are various specific definitions of rework depending on the industry under investigation, rework is generally understood to include the task or activities that must be done to fix defects, quality deviations, failings in functions or performance to comply with the original user requirements. This research is carried out with the Department of Space and Climate Physics at UCL, which has a strong motivation to understand the rework cycle as well as the different types of archetypes that affect space projects.

Systems dynamics is the principal method used to research rework in space projects. This is based on the use of graphical notation incorporating both qualitative and quantitative data (with the use of causal loop models and stock and flow models respectively) and is applied by designing the qualitative factors inside the scope of the study through literature review and surveys to experts in the field and elaborate diagrams of causality to comprehend in-depth the variables and the causes that affect rework. The quantitative data is then examined with simulation models that capture the complex behaviour of the systems, and results are gathered in a different graphical pattern allowing identification of systematic problems with the use of computer simulation models. Policies for improving the system or project are modelled to understand the potential benefits in a test environment; this ultimately enables a better understanding and management of problems.

[1]            United States Space Foundation., The space report 2014 : the authoritative guide to global space activity. 2014.

[2]            Government Accountability Office, “Assessments of Major Projects,” 2019.

[3]            M. Parchami Jalal and S. Shoar, “A hybrid SD-DEMATEL approach to develop a delay model for construction projects,” Eng. Constr. Archit. Manag., vol. 24, no. 4, pp. 629–651, Jul. 2017.


Juan Carlos Guerrero is a PhD student at University College London. He holds a Bachelor of Science in industrial engineering at the University of Americas (Ecuador). He also studied a master’s in occupational health and environment safety at University of San Francisco (Ecuador). Also, he holds a Master of Health Environmental Safety at the University of Huelva (Spain). Finally, Juan Carlos holds a master’s degree in systems engineering from the University of Queensland (Australia). He has achieved various international certifications in the field of statistical control and project management such as Black Belt Six Sigma and Project Manager Practitioner. He has had work experience in the private and also in the public sector, working in management activities within the division of quality and industrial safety, applying technologies to comply with international standards on quality, safety and environmental management, as well as, providing advisory services for the government of his home country on optimization of public services delivery through process improvement and systems implementation.