Selecting cost estimation methods that adequately fit the available data is difficult and holds great risks: Overly complex and time-consuming methods often lead to forcing assumptions that narrow the path for future development, while too simple methods that do not consider all known relevant data lead to lack of information.

The availability of data is closely linked to the progress of technology development. Technology readiness levels (TRL) are a popular concept for evaluating the maturity of development projects in government, industry and science. Since existing TRL guidelines remain unspecific to technologies, the need for a specification of TRL assessment for the chemical and process industries was identified. The first part of this paper gives detailed TRL criteria and indicators for the chemical and process industries.

The second part provides a guideline for the selection of adequate cost estimation methods by aligning existing estimation frameworks (e.g. AACE International classes) with the TRL scale and giving specific methods, estimation purposes and error ranges for each TRL. Finally appropriate indicators for economic assessment are proposed for each TRL.