Justus Holler

Can We Afford Integrity by Proof-of-Work? Scenarios Inspired by the Bitcoin Currency

Proof-of-Work (PoW), a well-known principle to ration resource access in client-server relations, is about to experience a renaissance as a mechanism to protect the integrity of a global state in distributed transaction systems under decentralized control. Most prominently, the Bitcoin cryptographic currency protocol leverages PoW to (1) prevent double spending and (2) establish scarcity, two essential properties of any electronic currency. This chapter asks the important question whether this approach is generally viable. Citing actual data, it provides a first cut of an answer by estimating the resource requirements, in terms of operating cost and ecological footprint, of a suitably dimensioned PoW infrastructure and comparing them to three attack scenarios. The analysis is inspired by Bitcoin, but generalizes to potential successors, which fix Bitcoin’s technical and economic teething troubles discussed in the literature.

Integrating Process Modeling Methodology, Language and Tool – A Design Science Approach

Providing high quality process models in a timely manner can be of major impact on almost all process management projects. Modeling methodologies in the form of normative procedure models and process modeling guidelines are available to facilitate this cause. Modeling languages and according tools, however, do neglect the available methodologies. Our work searches to close this research gap by proposing a modeling environment that integrates insights from modeling methodologies with a modeling language and a tool. Main features are a simple modeling language that generalizes most existing languages, four layers of abstraction and semantic standardization through a glossary and use of attributes. Our approach allows for rapid preparation of modeling activities and ensures high model quality during all modeling phases, thus minimizing rework of the models. The prototype was evaluated and improved during two practical projects.

Icebricks: business process modeling on the basis of semantic standardization

Within this article the prototype icebricks is described by its main characteristics which are layers of abstraction, attribution, reference models and semantic standardization by the use of a glossary. The layers are predefined in order to enhance the clarity and comparability of the processes. Attribution is used --- beside the layers of abstraction --- as means to reduce the complexity of the models by shifting information to analyzable and easily maintainable attributes instead of sophisticated control flows within the process elements. The glossary is inspired by the idea of model conventions. Each business object within it is defined once and can be used with defined activities as process building blocks within all models with the same semantic meaning. Furthermore, reference models are incorporated into the prototype to enable modelers with the possibility to create or derive purposeful models in a short period of time. The prototype was thoroughly and very successfully evaluated in its web based version in two process modeling projects aiming for process reorganization for an ERP system change and for a complete documentation of the process landscape for knowledge management.

Business Process Management in the Manufacturing Industry: ERP Replacement and ISO 9001 Recertification Supported by the icebricks Method

(a) Situation faced: A family-owned manufacturing company recently went through the transfer of management from the older to the younger family generation. A number of problems were uncovered during this process, such as prevalence of tacit knowledge, an inefficient decision-making process, outdated IT system support, and an urgent need for certification of production processes according to quality-assurance standards (ISO 9001). Each of these problems required thorough documentation of the as-is business processes in the organization to guide their improvement. (b) Action taken: To ensure that the created process models serve as a valid communication medium, the company’s process landscape was created during an initial workshop between the executives and external BPM consultants. Then the information on processes in the company’s various departments was gleaned from semi-structured interviews with the department employees. At the same time, process weaknesses and potential improvements were derived and discussed with the functions’ management. The succeeding depiction of the to-be process framework was achieved with the help of the icebricks modeling method and the corresponding software tool, which is a lightweight, standardized approach to ensure high quality of process models. (c) Results achieved: During the modeling phase of the project, external BPM consultants documented the process landscape, thereby explicating the company’s knowledge and good-practice processes. The process landscape served as basis for well-informed decisions regarding the implementation options of a new ERP system, which was introduced on time and on budget in the second phase of the project. The ISO 9001 recertification of production processes was achieved in the third project phase with the help of the process documentation that had been created. (d) Lessons learned: Simply deploying process models on the company’s intranet platform does not necessarily lead to their desired comprehension and use. All employees have to be trained that process models are a means of communication and are never finalized, a notion that also applies to continuous process improvement. Process owners must be defined so they take responsibility for adjustments to the process environment beyond the project’s lifecycle, but such responsibility is not solely that of a project manager. Furthermore, the project demonstrated the appropriateness of the icebricks modeling method for the manufacturing domain, although it was originally designed for the retail industry.

Towards Increased Comparability of Business Process Models: Design, Implementation and Evaluation of Semantic Standardization Functionality

Business Process Management (BPM) has become a widespread practice in organizations. Companies use business process models to document their internal processes for training purposes, optimization, certification or requirements specification. However, as the modeling projects are often carried out by distributed teams of BPM experts, the resulting models may suffer from naming variability conflicts. Variability makes the created models difficult to understand, to automatically analyze and to re-use. In order to avoid these pitfalls, modeling guidelines, such as use of domain-specific glossary and verb-object phrase structures for element labels, were suggested. However, methodological and tool support is rarely provided. Moreover, no effectiveness studies of semantic standardization functionality were yet conducted. We close this research gap by presenting a strategy for the implementation of semantic standardization functionality and put particular attention on the evaluation of its implementation. As a result of the evaluation, we highlight design decisions, which have an effect on the comparability of process models. The study is of interest to both, academics and practitioners, who work in the area of process modeling and intend to increase process model comparability.