Decision Support Cycle
The preceding chapters describe the DSP's parts. This chapter is about running it: how to begin, how the modelling platform feeds it, and how a first pass becomes a refined one.
What this chapter covers
| Page | What you will find |
|---|---|
| How to Get Started | Entry points, starting conditions, and the three levels of application |
| Integration with IMP | Which IMP outputs each DSP stage draws on, stage by stage |
| DSP First Pass | Running the six processes end to end for the first time |
| Second Pass / Refinement | Optioneering, optimisation and further evidence on a second iteration |
Only one of the four is written in the source
Integration with IMP is documented in full and is substantial.
How to Get Started, DSP First Pass and Second Pass / Refinement exist in the source handbook as headings with fourteen empty sub-headings between them. Nothing has been written in their place.
Each page sets out what the section should contain and links to the material elsewhere in the handbook that partially answers it. In the case of the two pass pages, most of the substance does exist within Technical processes; what is missing is the account that joins it up.
Why it is a cycle
The six process flows run from understanding the current system through to learning from outcomes, and then feeding that learning back into future decisions.
Three properties make it a cycle rather than a sequence:
| Property | Where it is stated |
|---|---|
| Outputs travel backwards as well as forwards | A process output informs subsequent or preceding processes. See definition of a process |
| Every stage iterates internally | All five documented processes carry their own iteration section |
| The last stage feeds the first | Outcome Assessment writes back to the Asset Registry, which is where evaluation begins |
Iteration has a stopping rule
Iterating without a stopping rule is just indecision. The handbook gives one, in Asset / Network Evaluation: iteration continues until the evidence is sufficient to support progression to the next stage, and complete certainty is not the target.
The relationship with the IMP in one view
The DSP and the IMP are the two halves of TPRAF. The DSP defines what needs deciding; the IMP supplies the quantified evidence.
| DSP | IMP | |
|---|---|---|
| Role | The decision-making structure | The analytical capability |
| Produces | The questions | The evidence |
| Can run alone? | Yes, where sufficient evidence already exists | Yes, its components can be used independently |
The two are at their most useful together, because that is what allows decisions to rest on quantified evidence rather than assumptions alone.
Full detail, including which IMP outputs each of the six DSP stages draws on, is in Integration with IMP.