The most important difference for your assessment tool: COBIT 5 had a detailed Process Assessment Model with specific indicators for each attribute level. COBIT 2019, by contrast, does have an official PAM. Instead, ISACA recommends using the Capability Maturity Model Integration (CMMI) to measure capability levels, combined with the detailed activity descriptions in the COBIT 2019 Framework: Governance and Management Objectives publication, which describes expected capability levels for each of the 1202 COBIT activities across the 40 objectives.
Do not try to assess all 40 objectives simultaneously unless resources are unlimited. Use the COBIT 2019 Design Factors worksheet to identify high-priority focus areas. Filter your Excel sheet to display only these scoped objectives. Step 2: Evidence and Data Gathering Cobit 2019 Maturity Assessment Tool Xls
Assess if the process outcomes are achieved at Level 1. The most important difference for your assessment tool: