Purpose – In spite of the increased research activity on inter-organizational cost management (IOCM) and open-book accounting (OBA), detailed evidence on the application of these tools in real-life settings is still relatively sparse. Increased outsourcing and supplier responsibilities call for more thorough understanding on the possibilities and variations of supply chain cost management. As a research avenue, in-depth case studies have been invited to elaborate the cost management interaction between companies. This paper aims to address these issues. Design/methodology/approach – This paper is based on an interventionist research within two supply networks. By making research interventions on the development of cost management practices among the suppliers, the researchers have set the ground for implementation of OBA, which, then, has provided a box seat to observe the process of OBA and its associations with the different forms of control. Within these two networks, this paper focuses on two OBA episodes portraying different facets of openness in IOCM. Findings – This paper presents OBA as an accounting template with a seemingly flexible character. By relying on the empirical study, the paper shows how OBA might be used for mitigating the component's price increasing pressures and, thus, controlling the costs of the end product in hybrids resembling very much market conditions. However, the very similar OBA procedures can be applied for achieving the long-term goals of partnering in hybrids resembling to a great extent hierarchical structures. As the paper shows, the best corresponding control archetype for a given OBA application largely depends on the purpose defined for the IOCM activity by participating stakeholders. Originality/value – Thus, far, there are no interventionist studies on OBA and, hence, the research setting provides an interesting new element to the extant literature on OBA and IOCM. However, the research method does not have intrinsic value. Thus, the contribution, and therefore also the originality, of this paper is based on new aspects provided to the theory on OBA.
