•Validates the need for a process capability maturity model for the digital transformation/smart manufacturing domain.•Develops a Digital Transformation Capability Maturity Model (DX-CMM) based on a well-accepted SPICE-ISO/IEC 330xx standard.•Applies DX-CMM to check its’ usability and applicability by the utilization of a qualitative multiple case study approach in two companies with different sectors, sizes, countries, and DX adoption. The utilization of on-premise technologies in the business environment is ushering in a new era known as digital transformation (DX). Although organizations are aware of the potential advantages of DX, they have faced problems creating a clear path to reshape their existing processes in line with on-premise technologies. Therefore, they need guidance from a holistic viewpoint. Maturity models (MMs) are developed to guide organizations by providing an extensive roadmap for improvement. The digital transformation capability maturity model (DX-CMM) is developed to assist organizations by providing current DX capability/maturity determination, derivation of a gap analysis, and the creation of a comprehensive roadmap for improvement in a comprehensive, structured, objective, complete, and standardized way. The aim of this study is to check the usability and applicability of the DX-CMM by performing a multiple case study, including assessments of the DX maturity level and derivation of a roadmap for DX maturity improvement to move one level further in two organizations in the chemical and machine manufacturing domains. The case study results show that the DX-CMM is applicable for identifying the DX maturity level, and it is capable of providing a roadmap for DX maturity improvement for moving one DX maturity level further, as well as benchmarking organizations evaluated using the same approach.