# ID-Service: A Blockchain-Based Platform to Support Digital-Identity-Aware Service Accountability
## 3 Case Study: A Biomass Production Chain  
Among the real-life cases in which our platform has been tested, we describe here its application to the field of biomass production. We chose this scenario mainly because the addressed problem is representative, complex, and timely. This case study is a good test-bed as it inherently involves Cross-Organizational Workflows, in which different and conflicting organisations cooperate for achieving a common goal (i.e., producing and delivering high-quality biomass to the final customer). Moreover, due to legal requirements, there is a strict need of accountability with respect to subjects with assured and publicly verifiable identity. Therefore, this domain collects all the requirements we fulfill in our platform. As a matter of fact, one of the industrial partners of the project works in this field (specifically, in the agro-energy sector), and the above considerations were the basis of the project partnership composition, also to test our solution in a real-life environment. The experimentation has been conducted during the run of the project, from September 2019 to March 2020. Selection of test objectsWe identified a process that could benefit from its integration with a blockchain-based technology. Specifically, we chose to model a biomass production chain, which involves many different organisations that cooperate to pursue a common goal, i.e., producing and delivering high-quality biomass. The process was chosen due to the existence of accountability and traceability issues [23; 24], and how adversely these impact the end product's quality. Accountability is a property of utmost importance in this domain due to the strict need for compliance to norms and regulations as well as the high level of legal and non-legal responsibilities related to actions performed by the participants. Traceability is another very important property, which is related to visibility, controllability, and security requirements. The production chain is characterised by intra and inter-organisation interactions. Research MethodologyThe chosen methodology included: (1) implementation of the selected process; (2) simulation and assessment; (3) performance analysis of blockchain features; (4) process mining analysis, after extraction of simulation logs from the blockchain. The accountability issue arises with inter-organisation interactions: while the identities of a group of employees are clearly defined within an organisation, thus enabling accountability, the same does not necessarily hold outside an organisation. The main idea behind the case study was to address the above-mentioned issues by integrating the process with a blockchain-based technology, combined with digital identities. See Section 3.2 for additional details on the implemented system. The result of such integration is a process in which actors that participate in inter-organisation interactions use an identity-based digital service to certify the operation(s) performed. The certification consists of writing an association between the actors' identity and operation-related documents on the blockchainso that a permanent record is created. The record will serve as a verifiable and immutable trace of what has happened between two participants. The domain process that was considered for the case study is briefly described below. The biomass production chain involves a lot of different actors which are the following: _landowner_, _supplier_, _wood company_, _transformer operator_, _electricity company_, _competent bodies_. Some of the mentioned actors may be represented by a single organisation: for example, supplier, wood company, and transformer operator may coincide. The process can be described with three macro activities, listed in order of execution: _Preliminary Activity_, _Building Site Activity_ and _Delivery Activity_. Below we briefly describe each of these activities, assuming that the supplier also acts as a wood company and transformer operator.