Defining Ideality as a TRIZ Concept
Ideality is one of the building blocks of the TRIZ logic. Defining Ideality is helpful to understanding where you currently are. You can use it to describe where you want to get to and it is essential when you are comparing options. Ideality is the ratio between all the good things you want (benefits) and any downsides (costs and harms).
Ideality = Ʃ Benefits / (Ʃ Costs + Ʃ Harms)
Benefits are all good outcomes. A list of benefits is a list of all the things that you want, without any detail of how you get them (benefits cannot contain solutions).
Costs are all inputs required to create your system, not just money but also time, resources and energy.
Harms are all outcomes you don’t want. Nothing is neutral in TRIZ – an outcome is either wanted (and a benefit) or not (and therefore a harm).