https://www.epo.org/en/node/what-qualitative-evaluation

What is qualitative evaluation and when is it used?

As quantitative evaluation only gives an indication of the estimated monetary value of the patent, this approach is often insufficient as a basis for recommending business strategy decisions. Qualitative evaluation goes further by identifying the strengths and weaknesses of the patent and creates a value guide through the rating and scoring of different factors related to the patent.

For example: Even if the outcome of a quantitative evaluation was, "The patent is worth EUR 50 000", the result of a qualitative evaluation could be, "The patent protects a technology of strategic importance for an attractive market; it can be enforced efficiently, but significant investment is still needed".

Qualitative evaluation methods are most often used for the purpose of internal patent management. They are most useful for comparing, categorising and ranking patents within a portfolio or vis-à-vis competitors' patents. They are also useful for assessing the risks and opportunities of patents.