Abstract Cloud service providers offer application providers with virtually infinite storage and computing resources, while providing cost-efficiency and various other quality of service (QoS) properties through a storage-as-a-service (StaaS) approach. Organizations also use multi-cloud or hybrid solutions by combining multiple public and/or private cloud service providers to avoid vendor lock-in, achieve high availability and performance, and optimise cost. Indeed cost is one of the important factors for organizations while adopting cloud storage; however, cloud storage providers offer complex pricing policies, including the actual storage cost and the cost related to additional services (e.g., network usage cost). In this article, we provide a detailed taxonomy of cloud storage cost and a taxonomy of other QoS elements, such as network performance, availability, and reliability. We also discuss various cost trade-offs, including storage and computation, storage and cache, and storage and network. Finally, we provide a cost comparison across different storage providers under different contexts and a set of user scenarios to demonstrate the complexity of cost structure and discuss existing literature for cloud storage selection and cost optimization. We aim that the work presented in this article will provide decision-makers and researchers focusing on cloud storage selection for data placement, cost modelling, and cost optimization with a better understanding and insights regarding the elements contributing to the storage cost and this complex problem domain.

Cloud computing has become an increasingly popular choice for businesses and individuals due to its flexibility, scalability, and convenience; however, the rising cost of cloud resources has become a significant concern for many. The pay-per-use model used in cloud computing means that costs can accumulate quickly, and the lack of visibility and control can result in unexpected expenses. The cost structure becomes even more complicated when dealing with hybrid or multi-cloud environments. For businesses, the cost of cloud computing can be a significant portion of their IT budget, and any savings can lead to better financial stability and competitiveness. In this respect, it is essential to manage cloud costs effectively. This requires a deep understanding of current resource utilization, forecasting future needs, and optimising resource utilization to control costs. To address this challenge, new tools and techniques are being developed to provide more visibility and control over cloud computing costs. In this respect, this paper explores a graph-based solution for modelling cost elements and cloud resources and potential ways to solve the resulting constraint problem of cost optimisation. We primarily consider utilization, cost, performance, and availability in this context. Such an approach will eventually help organizations make informed decisions about cloud resource placement and manage the costs of software applications and data workflows deployed in single, hybrid, or multi-cloud environments.

Providing services cost-effectively and rapidly in the current challenging e-business environment has transformed Web services emerging standards as a promising technology for automating interorganizational interactions. However, key issues such as B2B interactions modeling in business process collaboration and integration remain to be addressed. In this paper, we propose a conceptual model and architecture to effectively manage conversations between business processes and leverage Web services from mere software components to actual entities of a business interaction.

Web services offer an interoperability model that abstracts from the idiosyncrasies of specific implementations; they were introduced to address the increasing need for seamless interoperability between systems in the business-to-business domain. We analyse the requirements from this domain and show that to fully address interoperability demands we need to make use of semantic descriptions of Web services. We therefore introduce the Web service execution environment (WSMX), at software system that enables the creation and execution of semantic Web services based on the Web service modelling ontology. Providers can use it to register and offer their services and requesters can use it to dynamically discover and invoke relevant services. WSMX allows a requester to discover, mediate and invoke Web services in order to carry out its tasks, based on services available on the Internet.

The ultimate target of business to business (B2B) integration and deployment is complete business process automation within and between enterprises with no human intervention. From a business point of view, negotiation is the main mechanism that modern enterprises use to achieve targets that maximise their profits. This paper proposes an automated B2B negotiation solution: the implementation of semantic-enabled machine versus machine business negotiation as a Web service. We argue that the shift from human vs. human to machine vs. machine business negotiation is facilitated by using semantic Web technology implemented with Web services. The negotiation process in this work is designed for multiple machines (a minimum of 3 computers), using a negotiation algorithm that emulates the behaviour of human business negotiations. Possible development directions are brought forward in the paper's conclusion.

Integrating complex systems like application systems or whole enterprises by means of exchanging electronic business data requires not only the passing of the business data itself in form of business events between the systems but also ensuring that the relevant business events are passed at the right time as well as in the right order. This is called the integration problem: the formal definition and execution of the exchange sequence of business events between complex systems. Many insufficient standard proposals are currently being brought forward to address the integration problem. This contribution revisits the requirements of complex systems integration and proposes superior alternatives in approaching and solving the integration problem.

The tutorial "Software as a Service: ASP and ASP aggregation" will give an introduction and overview of the concept of "renting" access to software to customers (subscribers). Application service providers (ASPs) are enterprises hosting one or more applications and provide access to subscribers over the Internet by means of browser technology. Furthermore, the underlying technologies are discussed to enable application hosting. The concept of ASP aggregation is introduced to provide a single access point and a single sign-on capability to subscribers sub-scribing to more than one hosted application in more than one ASP.

The tutorial “Semantic B2B Integration” will give an introduction to the field of business-to-business (B2B) integration from a technical viewpoint with the focus on semantic integration aspects. The set of B2B integration concepts is introduced as well as their implementation in form of a technical semantic B2B integration architecture. A mix of examples is taken illustrating the problems that need to be solved in semantic B2B integration projects. The tutorial enables the audience to identify semantic B2B integration problems as well as to determine the benefits and deficiencies of various technical integration architecture approaches or B2B integration technologies.

Workflow Management System (WFMS) implementations traditionally follow a client/server architecture with monolithic servers (workflow engines). This poster presents a WFMS architecture based on a TP-Monitor environment which partitions the workflow engine into several resource managers (RMs) individually managed by a TP-Monitor environment. The RMs together form the workflow engine serving user requests.

In distributed workflow management systems (WfMSs) many workflow servers and application programs referenced within workflows have to work together cooperatively. We introduce a middleware service for WfMSs which offers qualities for client/server communication. These qualities characterize the behavior of clients and servers in case of failure and recovery. Our middleware service builds an abstraction from the concrete implementation of a client/server interaction and hides characteristics of underlying system services, e.g. RPC mechanisms and TP monitors. For this reason, our middleware service supports the implementation of reliable distributed WfMSs.

Application programs are a substantial asset of an organization. The introduction of workflow management technology must provide means and mechanisms to integrate existing application programs which are not aware of workflow management systems in the same seamless manner as newly written, workflow-aware applications. The paper presents a general approach for integrating workflow-unaware application programs into workflow management systems. Their concepts enable the integration of application programs which are implemented on top of heterogeneous operating systems or base services into our prototype workflow management system MOBILE. Furthermore, they support the execution of several transactional application programs within a single transaction controlled by the workflow management system.