Author’s reply to: David Elms’ discussion of ‘a framework for a civil engineering BOK’

I read Professor Elms’ contribution to the Special Issue (Elms, 2020) several times. It contains a lot of food for thought. Of particular interest is Table 1 ‘Commentary onmodels and modelling’ of that paper. What Professor Elmswrites is compatible with the BOK Framework in Carmichael (2020). To understand the compatibility introduces a level of trickiness, something that is difficult to explain to students and for students to understand because of a sort of circularity it introduces. The level of trickiness is like saying that ‘a model is a representation of a system, yet a model is a system’, and ‘models may model models’ (at which point students say that they wanted to become engineers not philosophers, and they head instead towards the laboratories to do some less-challenging breaking of concrete). The following is not a criticism of Elms (2020), because by and large I do not disagree with his views; rather it is an attempt at a reconciliation. Some of the differences between Professor Elms’ work and mine comes down to terminology – I comment on terminology in Carmichael (2020) and in a discussion piece to this Special Issue. It is my belief that agreement on terminology is a large factor in holding back the development of a Civil Engineering Systems BOK. I always attempt to be disciplined in the use of terminology; I always try to use terms, for example, ‘system’, ‘model’, ‘problem’, ‘uncertainty’, ‘risk’ and so on, in a consistent way and with only one meaning each. In the Elms (2020) paper Table 1, many issues are discussed regarding the choice or aide memoire for models and model building, and also in the Elms discussion piece, the terms ‘purpose’, ‘situation’ etc. are raised. The trickiness that throws students is that Professor Elms, when talking about selecting a model, is in fact performing what is referred to as ‘synthesis’ or ‘design’ (Part F) in the proposed BOK Framework in Carmichael (2020). Professor Elms is ‘designing’ the model. This is separate to systems design which I raise at Part F of the proposed BOK Framework. In effect, a fully developed Part F of the BOK Framework would cover all design issues which could be applied to any system (including a model if it is interpreted as a system). This includes issues about iterations in design, creativity, uncertainty and so on. The intangibles and subjectivity spoken of by Elms could also be incorporated. (But thinking of the necessary background to ‘designing’ a model only hastens the students to the concrete laboratory because of the logic loops that it introduces.)