Hazhir Rahmandad

 

 

Research

I am interested in understanding the dynamics of socio-technical systems. I am an expert in System Dynamics and Agent Based modeling methodologies. I employ simulation models to build and test theories of organizational and social phenomena using qualitative and quantitative data, and analyze policy using simulation. I am interested in applying these tools in a diverse set of phenomena, including product development, organizational learning and change, sustainability, and health care. Learning and tradeoffs between short and long term are common unifying themes in what I study. Moreover, I am interested in expanding the simulation toolbox in social sciences by bridging different simulation methodologies and building on advances in control theory and artificial intelligence to enhance model calibration and optimization. Specifically, I have recently worked on the following research areas:

 

Modeling Methodologies

 - When is it better to use agent-based (AB) models, and when should differential equation (DE) models be used? AB models enhance realism but entail computational and cognitive costs that may limit sensitivity analysis and model scope. In collaboration with Professor Sterman we have studied this question in the context of epidemics diffusion, comparing an agent based model of disease spread with its differential equation counter part. The paper, published in Management Science, is available below, along with supplementary material.

- What are the best formulations and methods for modeling dynamics of projects? In collaboration with one of my Ph.D. students, Kun Hu, we have compared four alternative formulations for modeling the rework cycle, from the most basic differential equation formulations to fairly complex agent-based ones. We discuss the capabilities and limitations of each formulation.

 

Product Development

- Why is it hard to build and sustain product development capability in the context of multiple-release product development? In collaboration with Professor Repenning, I have conducted two case studies of software product development to understand why quality and delay issues persist in a multi-release setting, despite the potential for learning from experience, and why it is hard to build and sustain the PD capability.

 

 - What dynamic processes complicate the building and maintenance of a successful software organizations? In collaboration with Dr. Weiss we have explored a set of reinforcing feedback processes that cut across multiple releases of a software and introduce tipping dynamics in software organizations involved in concurrent development practices. This paper is forthcoming in System Dynamics Review.

 

Organizational Learning and Delays

- How delays impact the complexity of organizational learning? I investigate this problem using a Q-learning algorithm to capture speed and quality of organizational learning in the presence of delays between action and payoff. Results suggest that learning complexity can grow exponentially with the size of delays and that suboptimal strategies may dominate the organizational action because of biases in valuing and therefore trying the actions that take time to payoff. The paper is published in Management Science.

- How is organizational learning influenced by delays inherent between taking actions and seeing the results? Such delays are wide-spread, from investments in capacity, process improvement, and maintenance, to daily decisions on how much to attend to quality of work. I have worked on this question with Professors John Sterman and Nelson Repenning.

- How does competition and endogeneity of resources available to a firm impact the tradeoffs they face between short-term and long-term policies? Tradeoffs between short-term and long-term are an important and complex issue for managers to deal with. In this paper I discuss how competition and endogeneity of resources impact those tradeoffs.

 

You can find more details about my education and background in my C.V.

 

Papers and publications:

  • Rahmandad, H. (2008). "Effect of delays on complexity of organizational learning." Management Science 54(7): 1297-1312.
  • Rahmandad, H. and J. Sterman (2008). "Heterogeneity and network structure in the dynamics of diffusion: Comparing agent-based and differential equation models." Management Science 54(5): 998-1014.

o        Rahmandad, H. and D. Weiss. (2009). Managing Reinforcing Dynamics in Software Organizations. Forthcoming, System Dynamics Review.

o        Rahmandad, H., N. P. Repenning and J. D. Sterman. (2008). Effect of Feedback Delays on Learning, Forthcoming, System Dynamics Review.

o        Rahmandad, H. and N. Repenning, (2008). Dynamics of Capability Development and Erosion, Working Paper

o        Rahmandad, H. (2008). Impact of growth opportunities and competition on dynamics of capability development. Under review in Organization Science.

  • Rahmandad, H. and K. Hu (2008). "Modeling rework cycle: comparing alternative formulations." Under Review in System Dynamics Review.
  • Rahmandad, H. and S. Fallah-Fini, Learning Control Policies in System Dynamics Models, in International System Dynamics Conference. (2008): Athens.

o        Rahmandad, H. (2007). Dynamics of Organizational Capabilities and Firm Adaptation, Working Paper

o        Rahmandad, H. and J. V. d. Cunha. (2001). Tightening the Iron Cage or Path Dependence in Norm Formation? A System Dynamics Approach. The 19th International Conference of the System Dynamics Society, Atlanta, Georgia, System Dynamics Society.

o        Rahmandad, H. 2000. Developing a Model for Paradigm Shift in Service Industry. 18th International Conference of the System Dynamics Society, Bergen, Norway, System Dynamics Society.

  • Rahmandad, H. and M. S. Pazhooh. 2000. A System Dynamics Approach to Organization Design: Case of Talented Students' Center in Sharif University of Technology. 18th International Conference of the System Dynamics Society, Bergen, Norway, System Dynamics Society.

 

 

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