Technological innovation is playing an increasingly important role in the current rapid technological change and globalization. In producing technological innovation, Technological Innovation Capability (TIC) is needed to be assessed and developed. Nevertheless, there is limited knowledge of how to measure TIC. This is similar to the situation in Thailand, the country in south-east Asia, that the government has recently promoted the new economic development model to be innovation-driven. The studies of TIC assessment in Thailand are still limited as they do not consider a TIC development, especially in Thai SMEs and start-ups. This study is anticipated to use Action Design Research (ADR) to build a tool for assessing and developing TIC by applying the concept of Innovation Capability Maturity Model (ICMM). Designing does not mean only building the products for commercialization; however, designing the solutions is one of the essential methods in the modes of business as it is the way to solve problems and grow a successful business. The mock-up of the tool will be proposed, and the interview with target users, which are Thai SMEs and start-ups will be conducted to acquire their insights on using the mock-up. The difficulties and key requirements for the solutions will be identified.