The subject of this thesis is the development and evaluation of a modular well intervention business concept. The concept aims to bridge the gap between surface and subsea well intervention markets, currently served by different vessel types, using a platform vessel and equipment modules. The regional scope is South-East Asia, due to its low subsea intervention demand making it difficult for dedicated subsea intervention vessels to operate all-year round. The concept is evaluated from the point of view of the vessel owner and is limited to light and mediumwell interventions. The thesis consists of concept development