Tag Archives: hierarchical process modelling

Modelling HPM as a PSM, using HPM

I conclude my book on Problem Structuring with some comments on a processual turn in Operational Research (Yearworth, 2025) and specifically comment

“In modelling the world processually we can also model our interventions within the same model … Or put more simply, problematic situations are processes as are the means of intervention.” (p. 270). 

Modelling our interventions specifically requires the possibility of representing our use of a problem structuring method as a model. Checkland and Poulter described the process of using Soft Systems Methodology (SSM) in the activity system ‘language’ of SSM itself (Checkland & Poulter, 2006, p. 194; Yearworth, 2025, p. 78). Checkland and Scholes went further and modelled the system to use SSM in the same purposeful activity system language i.e., the ongoing reflective practice of using SSM in client engagements (Checkland & Scholes, 1990, p. 294).  

The same approach has been used for describing the use of Hierarchical Process Models (HPM) for problem structuring. This was first manifest in the STEEP Project as means of self-evaluation of how well the methodology was performing, making use of the Italian Flag as a means of capturing judgement of process performance (Yearworth et al., 2015, p. 9). In the Healthy Resilient Cities project (Yearworth, 2015), we started to model the process of using the PSM within the model of the problematic situation itself (Yearworth, 2025, p. 173) i.e., the process <Improving the resilience of healthcare provisioning in Bristol…> contained within it the process <Using problem structuring>. Further work on exploiting the Italian Flag for capturing judgements of process performance in the use of a PSM was explored in depth by Lowe, Espinosa and Yearworth (2020).

The development of HPM as a PSM is described fully in Chapters 9 and 10 of my book. However, the work of modelling HPM as a PSM using HPM itself that was started in the STEEP project is still ongoing. The following shows its current incarnation in Strategyfinder.

HPM of using HPM as a PSM

Note that methodological learning, an essential element of using a PSM, is reflected in the model at Process #26 <Evaluating the engagement and improving our understanding …> and the processes it contains. The model also references other models that could be incorporated as enhancements, for example using the framework for improving facilitation developed by Ackermann (1996, p. 95), which has been interpreted in my book as another process model (Yearworth, 2025, p. 108). This illustrates the property that all HPM are composable according to their necessity and sufficiency for the success of the process that acts as the anchor for incorporation.

Ackermann, F. (1996). Participants’ perceptions on the role of facilitators using group decision support systems. Group Decision and Negotiation, 5(1), 93-112. https://doi.org/10.1007/BF02404178

Checkland, P., & Poulter, J. (2006). Learning for action : a short definitive account of soft systems methodology, and its use for practitioner, teachers and students. John Wiley & Sons: Chichester. 

Checkland, P., & Scholes, J. (1990). Soft systems methodology in action. John Wiley & Sons: Chichester. 

Lowe, D., Espinosa, A., & Yearworth, M. (2020). Constitutive rules for guiding the use of the viable system model: Reflections on practice. European Journal of Operational Research, 287(3), 1014-1035. https://doi.org/10.1016/j.ejor.2020.05.030

Yearworth, M. (2015). Healthy Resilient Cities: Building a Business Case for Adaption (NERC NE/N007638/1)[Grant]. Bristol. http://gotw.nerc.ac.uk/list_full.asp?pcode=NE%2FN007638%2F1

Yearworth, M. (2025). Problem Structuring: Methodology in Practice (1st ed.). John Wiley & Sons, Inc.: Hoboken. https://doi.org/10.1002/9781119744856

Yearworth, M., Schien, D., Burger, K., Shabajee, P., & Freeman, R. (2015). STEEP Project Deliverable D2.1(R2) – Energy Master Plan Process Modelling. STEEP PROJECT (314277) – Systems Thinking for Comprehensive City Efficient Energy Planning, pp78. Retrieved 26th January 2023, from https://www.grounded.systems/wp-content/uploads/2023/01/01_STEEP_D2.1_Energy_Master_Plan_process_model_update_M24_DEF_sent.pdf

Problem Structuring : Methodology in Practice

My new book is now available!

Current perspectives on approaches to problem structuring in operational research and engineering and prospects for problem structuring methods applicable to a wide range of practice.

Despite the myriad successes of Operational Research (OR) in government and industry, critique of its continued relevance to complex, wicked problems led to the emergence and evolution of Soft OR as a more humanist orientation of the discipline centred on a methodological framing of techniques known as Problem Structuring Methods (PSMs). These have enabled OR practitioners to broaden the scope of OR to address complex problem contexts that require transforming, planning and strategising interventions for their clients. The original core PSMs of Soft Systems Methodology (SSM), Strategic Options Development and Analysis (SODA) and the Strategic Choice Approach (SCA) are presented using a new analytical framework based on constitutive rules, epistemologies, and affordances of the modelling approach. Practical considerations in PSM based interventions are discussed emphasising trust-building, stakeholder identification, facilitation and ethical practice. A wide range of PSM applications are surveyed demonstrating clear intersections with communities of practice grounded in the applied social sciences. The development of a new PSM based on Hierarchical Process Modelling (HPM) of purpose arising from a processual turn in engineering practice offers additional insights for the practice of Soft OR. New developments in PSM practice built on use of Group Support Systems (GSS) and exploiting developments in machine learning are presented. Prospects for bringing the Soft OR project back into better alignment with mainstream OR are discussed in the context of new education programs and a possible processual turn in OR.

Problem Structuring: Methodology in Practice contains four linked sections that cover:

  1. Problem formulation when dealing with wicked problems, justification for a methodological approach, the emergence of soft OR, the relevance of pragmatic philosophy to OR practice.  
  2. Traces debates and issues in OR leading to the emergence of soft OR, comparative analysis of PSMs leading to a generic framework for soft OR practice, addressing practical considerations in delivering PSM interventions.
  3. Charts the emergence of a problem structuring sensibility in engineering practice, introduces a new PSM based on hierarchical process modelling (HPM) supported by teaching and case studies, makes the case for a processual turn in engineering practice supported by HPM with relevance to OR practice.
  4. Evaluation of PSM interventions, survey of applications, use of group support systems, new developments supported by machine learning, re-contextualising soft OR practice.

Problem Structuring: Methodology in Practice is a thought-provoking and highly valuable resource relevant to all “students of problems.” It is suitable for any UK Level 7 (or equivalent) programme in OR, engineering, or applied social science where a reflective, methodological approach to dealing with wicked problems is an essential requirement for practice.