Applying the same test-and-iterate discipline used on products to your own company's business model, including being willing to cannibalize an existing revenue stream. Osterwalder's own example: Strategyzer shifted from a consulting-fee model (billing clients for Osterwalder's and colleagues' time) to a licensed "programs on platforms" model, eventually telling clients directly that they no longer needed Strategyzer as consultants.
This is the practical, self-applied companion to Business Model Canvas and Value Proposition Canvas / Value Proposition Design: rather than only running discovery on customer-facing products, run it on the revenue model itself, and treat "our current business model" as one more hypothesis to be tested rather than a fixed constraint.