System Formulation

Document the model development

Document the simulation model

As you are approaching the end of the Formulation Step, it is very useful to take a step back and make a final review of your team’s work. As the formulation of the Virtual System’s ESE model is not an easy or one-track task, keeping a thorough documentation of every step you had to follow will facilitate you in many ways. First of all it will help you proceed to the Appraisal Step and the Output Step and will facilitate your communication with your Reference group. It is important for you to be able to explain your model in simple terms and defend its credibility, as it will assist in building trust between your team and your Reference Group. Additionally, the SAF is an iterative process. If your implementation is successful you might need to get back and revise or even expand your model in order to answer alternative policy questions. In that case a thorough documentation can be very helpful and save a lot of valuable time. Last but not least a well structured documentation will help you gain as much scientific added value as possible as it will assist you in producing well-structured and complete scientific publications, if you wish so.

Revise the tables of inputs and processes

The Input and Process Tables you have constructed in the early stages of the Formulation Step must be reviewed and revised during this stage. The Input Table will know receive its final form, at least for your current application. You must ensure that the table includes all the Inputs that you have used, all the aspects that were described in the correspondent subtask, the actual period for which you have the input data, the time interval, any modifications you had to make to the data, any approximations you made and also for those inputs that you haven’t to managed to acquire you should note how you dealt with that and the estimated difference it would make to the simulation analysis if you had that missing data/information. That way if at some point in the future these data/information becomes available you will be able to decide if including it to your ESE model is necessary or not. Finally you must be sure to include all the information regarding the property rights of the inputs in order to make the proper citations when necessary.

It is advisable that you keep revising your Process Table accordingly to the changes and refinements you make to the actual model components, as it is much easier that way than trying to do all the changes in the end. You should keep track of all the changes you have performed to the used equations and also provide explanation for those actions. It also of use to include in this table (or a separate one) the values and origin of the parameters used in each equation. Finally you must be sure to include all the literature references as appropriate.

Document the model and its testing.
For your own facilitation it is advisable that you take some time and prepare a documentation report of your ESE model. The best thing to do is to keep notes from all the actions taken from the beginning of the model’s formulation until the end, regarding all the three components (if there are so). In the end of the Formulation Step you can consolidate all these information, review it and include it in your final report. You should provide a scientific critique of the ESE components including the error estimates, the sensitivity to variations of the inputs, any quantitative indicators that might be useful in the outputs, and a preliminary qualitative assessment for the outputs of the model. You should also include the initial and revised conceptual model of the Virtual System along with detailed documentations of the reasons behind the revision. Regarding the validations, sensitivity tests and calibration procedures that you might have contacted various times throughout the different formulation stages, you should try to incorporate to the report as much detail as possible. Nevertheless, if you feel that some information is being repeated again and again in your draft notes, then you should incorporate to the report the results taken from the checks made at the final stage of your model and make sure that you add a comment about the actions taken earlier in the Formulation Step.

Finalize Scenarios
You should also conduct an iterative review of the wording of the scenarios you have selected with your Reference Group during the Design Step and also of their specifications. At this point you must be in a position to evaluate if it is feasible to run these scenarios with your ESE model. In some (extreme) cases you must abandon some scenarios or, more probably, change the wording in order to make them compatible with the ESE model’s possibilities. In case you have to make major changes to your scenarios you should communicate them to your Reference group and also document them in you report with detail regarding the reasons that led you to the changes.

Review Preparations for Interpretive Analysis
In some of the previous subtasks you should have outlined the interpretive analysis and check its compatibility with the ESE component models. In this stage you should review it with respect to the distinction between the analyses that will be directly associated with the simulation model outputs and any other that will provide additional evaluations relevant to specific scenarios.

Move on to the Appraisal Step