Rather than just tracking IT metrics (the DevOps four, etc), track how digital transformation spend effects business outcomes, e.g., in insurance:
Increase revenue. Gross written premiums (GWP) and gross earned premiums are insurers' primary revenue drivers. To increase these, insurers must either sell more policies to new or existing customers or increase the policy value per customer. Digital technologies can help insurers design and develop tailored products; optimize marketing and sales to attract new customers and create opportunities to cross-sell or upsell existing customers; provide better service to foster customer loyalty; empower agents with digital tools to boost effectiveness and productivity; and improve engagement to retain customers.
How you link something like moving to an event drive architecture to that could be tough. If you're tracking all your design theories and back them up with observations of what users do ("we made this a single page rather than a wizard, and more people signed up"), you're be pretty well positioned.
Original source: Forrester report, Build A Business Case For Digital Insurance Transformation