Treatment decision-making can be complex, notably when there are multiple treatments available, with different (probabilities of) benefits and harms, for example, survival and side effects.1 It is precisely in these complex situations that the preferences of the patient are of utmost importance, as the trade-offs of benefits and harms are subjective and concern patients' lives.2 In such trade-offs, shared decision making (SDM) has gained momentum as a strategy to include both the best available evidence and the patient's preferences.3

To support shared decision-making (SDM), in- itiatives are often focussed mainly on communication in the en- counter and the use of decision aids. Our previous research (Griffioen et al. Cancer Med 2021) revealed: decision-making as a sequence of (un)planned moments before, during, after the con- sultation; work for patients and relatives to acquire/understand/re- call information; often unclear roles and tasks, and unexpected energy drains (due to, e.g., changes in the trajectory). We aimed to develop a service design methodology to improve SDM. The entire patient journey is considered a service. All ‘touch points’ (leaflets, devices, etc.) become parts of a consistent service, supporting stakeholders’ decision making. We used oncology as a case.