Manufacturing companies are facing the fourth industrial revolution, which concerns itself with the real-time data-based communication and connection between cyber-physical systems and people. To initiate a successful digital transformation, many organizations turn to Industry 4.0 maturity models for orientation and advice. This paper aims to enable companies to find the model that suits them best. Therefore, several existing models are introduced and two of them, a quick-assessment model (CCMS) and a more extensive approach (Industry 4.0 Maturity Index), are described in detail. These two complementing models are combined into a new resource-efficient approach to assessing Industry 4.0 maturity.