*2.1. Supply Chain Governance*

Supply chain governance is a multi-faceted term used in various disciplines of academia and practice, such as political or economic science [14]. Supply chain governance refers to a concept for managing and coordinating business relationships between companies by providing a behavioral and decision-making framework when conducting transactions [15]. Governance aims to increase value creation in the supply chain and avoid opportunism [16,17]. While governance itself is not an activity, GMs are used to actively influence partners' behavior in business relationships.

GMs are distinguished into formal and informal mechanisms. Formal GMs are characterized by clear structures, which are often contractually defined. Formal mechanisms, such as contracts, establish a set of mutually accepted and required behaviors that define how to interact in the supply network [18]. Formal standards serve to specify product quality and define certain process requirements. Furthermore, the formal definition of roles and functions between organizations and individuals in a supply chain is another important mechanism within formal coordination [19].

Informal GMs, also called relational or social GMs, are based on a social, non-contractual level [20–22]. They enforce certain behavior in business relationships on a social–relational level (e.g., through social identification with the relationship or social pressure). Shared norms and values, repetitive social interactions, and trust build the basis of informal mechanisms. Informal mechanisms, such as an open communication culture and a willingness to comprise, provide substantial support for the coordination of business relationships [18,23]. Poppo and Zenger [23] emphasize that formal and informal governance are not substitutes for each other but support each other. Informal governance can, for example, be used to fill contractual gaps [24].
