Tag Archives: paradigm shifts

Disruptive change required to avoid existential threats

Decorative ink drawing by Zahrah Resh 2005It is easy for ideas or plans for transformational change to transition into transactional processes that deliver only incremental change.  Transformational change is about major shifts in culture, strategy or technology that causes substantial alterations in structure, organisation, behaviour and performance; whereas transactional changes occur within the existing structure and organisation.  Leading transformational change is hard and requires courage, vision, a willingness to listen to all stakeholders, decisiveness and communication, i.e. procedural justice and fair processes [see ‘Advice to abbots and other leaders‘ on November 13th, 2019].  If any of these components are absent, especially courage, vision and decisiveness, then transformational change can transition to a transactional process with incremental outcomes.  When the need to change becomes urgent due to existential threats, the focus should be on disruptive change [see ‘The disruptive benefit of innovation‘ on May 23rd 2018] but there is a tendency to avoid  such transformations and retreat into transactional processes that provide the illusion of progress.  Perhaps this is because transformational change requires leaders to be selfless, courageous and to do the right thing not just the easy thing [see ‘Inspirational leadership‘ on March 22nd, 2017]; whereas transactional processes occur within existing frameworks and hence minimise psychological entropy and stress [see ‘Psychological entropy increased by ineffectual leaders‘ on February 10th, 2021].  This tendency to avoid disruptive change happens at all levels in society from individual decisions about lifestyle, through product development in companies, to global conferences on climate change [see ‘Where we are and what we have‘ on November 24th, 2021].

Image: Ink drawing by Zahrah Resh, 2005. See ‘Seasons Greetings in 2020‘ on December 23rd, 2020.

Acknowledgement: thank you to a regular reader of this blog for the stimulating this post with a comment about transformational change left to the last minute becoming transactional.


Hierarchical modelling in engineering and biology

In the 1979 Glenn Harris proposed an analytical hierarchy of models for estimating tactical force effectiveness for the US Army which was represented as a pyramid with four layers with a theatre/campaign simulation at the apex supported by mission level simulations below which was engagement model and engineering models of assets/equipment at the base.  The idea was adopted by the aerospace industry [see the graphic on the left] who place the complete aircraft on the apex supported by systems, sub-systems and components beneath in increasing numbers with the pyramid divided vertically in half to represent physical tests on one side and simulations on the other.  This represents the need to validate predictions from computational models with measurements in the real-world [see post on ‘Model validation‘ on September 18th, 2012]. These diagrams are schematic representations used by engineers to plan and organise the extensive programmes of modelling and physical testing undertaken during the design of new aircraft [see post on ‘Models as fables‘ on March 16th, 2016].  The objective of the MOTIVATE research project is to reduce quantity and increase the quality of the physical tests so that pyramid becomes lop-sided, i.e. the triangle representing the experiments and tests is a much thinner slice than the one representing the modelling and simulations [see post on ‘Brave New World‘ on January 10th, 2018].

At the same time, I am working with colleagues in toxicology on approaches to establishing credibility in predictive models for chemical risk assessment.  I have constructed an equivalent pyramid to represent the system hierarchy which is shown on the right in the graphic.  The challenge is the lack of measurement data in the top left of the pyramid, for both moral and legal reasons, which means that there is very limited real-world data available to confirm the predictions from computational models represented on the right of the pyramid.  In other words, my colleagues in toxicology, and computational biology in general, are where my collaborators in the aerospace industry would like to be while my collaborators in the aerospace want to be where the computational biologists find themselves already.  The challenge is that in both cases a paradigm shift is required from objectivism toward relativism;  since, in the absence of comprehensive real-world measurement data, validation or confirmation of predictions becomes a social process involving judgement about where the predictions lie on a continuum of usefulness.


Harris GL, Computer models, laboratory simulators, and test ranges: meeting the challenge of estimating tactical force effectiveness in the 1980’s, US Army Command and General Staff College, May 1979.

Trevisani DA & Sisti AF, Air Force hierarchy of models: a look inside the great pyramid, Proc. SPIE 4026, Enabling Technology for Simulation Science IV, 23 June 2000.

Patterson EA & Whelan MP, A framework to establish credibility of computational models in biology, Progress in Biophysics and Molecular Biology, 129:13-19, 2017.