First, it is determined who the relevant stakeholders are, during the stakeholder identification [1, 2]. For example, a scoping review of scientific literature is a suitable way to gain quick insight in the stakeholders that might be present. Such a list is often used as a starting point, from which to further progress towards insight in who the stakeholders for your specific case are. For instance by asking known experts in the field to identify who they perceive as being stakeholders, which is called expert recommendations. Besides the experts, the stakeholders themselves may also have clear ideas about who other stakeholders are, which is referred to as snowball sampling.
The end result of stakeholder identification is a (long) list or visualized map of stakeholders that is generated based on literature, e.g. via a scoping review, and practice, e.g. via expert recommendations or snowball sampling). In many situations, a lot of stakeholders are at play. However, it is often impossible or even undesirable to involve them all in the development process. Therefore, the next step is to determine who the key stakeholders are and what their stakes are by means of a stakeholder analysis.
 Velsen, L. van, Wentzel, J., & van Gemert-Pijnen, J.E. (2013). Designing eHealth that Matters via a Multidisciplinary Requirements Development Approach. JMIR Research Protocols, 2(1): e21.
 Woezik, A.F. van, Braakman-Jansen, L.M., Kulyk, O., Siemons, L., & van Gemert-Pijnen, J.E. (2016). Tackling wicked problems in infection prevention and control: a guideline for co-creation with stakeholders. Antimicrobial Resistance & Infection Control, 5:20.