Manuel Resinas

Defining process performance indicators: an ontological approach

It is increasingly important to evaluate the performance of business processes. A key instrument to carry out this evaluation is by means of Process Performance Indicators (PPIs) as suggested in many methodologies and frameworks like, for instance, COBIT, ITIL or EFQM. As a consequence, it is convenient to integrate the management of PPIs into the whole business process lifecycle from its design to its evaluation. In this paper, we focus on the definition of PPIs as a necessary step to achieve that integration. Unfortunately, current proposals are not able to specify several usual types of PPIs, specially those related to data, and are not well designed to enable the automated analysis of PPIs at design-time. In this paper, we present an ontology for the definition of process performance indicators that overcomes this issue, explicitly defines the relationships between the indicators and the elements defined in a business process modelled in BPMN, and enables the analysis of PPIs at design-time. Furthermore, this ontology has been validated by means of several real-world scenarios.

Improving Temporal-Awareness of WS-Agreement

WS-Agreement (WS-Ag) is a proposed recommendation of the Open Grid Forum that provides a schema to describe SLAs and a protocol to create them based on a mechanism of templates. However, although it identifies the necessity of specifying temporal-aware agreement terms (e.g. the response time is 30 ms from 8:00h to 17:00h and 15 ms from 17:00h to 8:00h), to the best of our knowledge, there are no existing proposals that deal with that necessity. We propose an extension that gives WS-Ag support to temporality. This allows describing expressive validity periods such as those composed by several periodic or non-periodic intervals and it applies not only to the agreement terms themselves but also to other parts of WS-Ag such as creation constraints and preferences about the service properties. In addition, in this paper we propose a preference XML schemato describe preferences over any set of service properties using any kind of utility function. In further research we will study a concrete specification for those utility functions.

An Hybrid, QoS-Aware Discovery of Semantic Web Services Using Constraint Programming

Most Semantic Web Services discovery approaches are not well suited when using complex relational, arithmetic and logical expressions, because they are usually based on Description Logics. Moreover, these kind of expressions usually appear when discovery is performed including Quality-of-Service conditions. In this work, we present an hybrid discovery process for Semantic Web Services that takes care of QoS conditions. Our approach splits discovery into stages, using different engines in each one, depending on its search nature. This architecture is extensible and loosely coupled, allowing the addition of discovery engines at will. In order to perform QoS -aware discovery, we propose a stage that uses Constraint Programming, that allows to use complex QoS conditions within discovery queries. Furthermore, it is possible to obtain the optimal offer that fulfills a given demand using this approach.

RALph: A Graphical Notation for Resource Assignments in Business Processes

The business process (BP) resource perspective deals with the management of human as well as non-human resources throughout the process lifecycle. Although it has received increasing attention recently, there exists no graphical notation for it up until now that is both expressive enough to cover well-known resource selection conditions and independent of any BP modelling language. In this paper, we introduce RALph, a graphical notation for the assignment of human resources to BP activities. We define its semantics by mapping this notation to a language that has been formally defined in description logics, which enables its automated analysis. Although we show how RALph can be seamlessly integrated with BPMN, it is noteworthy that the notation is independent of the BP modelling language. Altogether, RALph will foster the visual modelling of the resource perspective in BPs.

Automated Analysis of Conflicts in WS-Agreement

WS-Agreement is one of the most widely used SLA specifications. An advantage of WS-Agreement over other agreement metamodels is that it allows one to define conditional and optional term sets inside an agreement document, which are commonly found features in real-world agreements. Unfortunately, they increase the complexity of the automated detection and explanation of conflicts between SLA terms, leading to new kinds of conflicts that are not supported by current techniques. Furthermore, creating a general-purpose conflict analyser in WS-Agreement is a hard task since it should understand the semantics of an unbounded number of languages that can be used in the eight extension points that WS-Agreement includes for the sake of flexibility. In this article, we address these issues by providing a conflict classification for SLAs that includes new conflicts derived from the use of conditional and optional term sets; and a novel language-agnostic technique based on constraint satisfaction problems to automatically detect and explain these conflicts. In pursuing these results, we defined some WS-Agreement concepts as well as a fully-fledged WS-Agreement-compliant language. The developed technique and its reference implementation have been thoroughly validated.

RAL: A High-Level User-Oriented Resource Assignment Language for Business Processes

An important task of business process design is the definition of what and how members of an organization are involved in the activities of the business processes developed within it. In this paper we analyse the capabilities of BPMN 2.0, the de-facto standard for business process modelling, in this regard. The conclusion is that, although it provides some mechanisms to assign resources to business process activities, they present several drawbacks. On the one hand, it does not provide a clear way to relate the assignment of resources with a model of the structure of the organization. On the other hand, it relies on XPath as the default language to assign resources to activities. The consequence is that it has limitations regarding the expressiveness of resource assignment expressions. Furthermore, it makes resource assignment not easy to learn and use since XPath has not been designed for that purpose. To overcome these drawbacks we introduce RAL (Resource Assignment Language), a DSL based on a well-known organizational metamodel that can be used together with BPMN 2.0. RAL provides more expressiveness to the resource assignments and it uses a high-level sintaxis defined to be used by technically unskilled users.

A bargaining-specific architecture for supporting automated service agreement negotiation systems

The provision of services is often regulated by means of agreements that must be negotiated beforehand. Automating such negotiations is appealing insofar as it overcomes one of the most often cited shortcomings of human negotiation: slowness. Our analysis of the requirements of automated negotiation systems in open environments suggests that some of them cannot be tackled in a protocol-independent manner, which motivates the need for a protocol-specific architecture. However, current state-of-the-art bargaining architectures fail to address all of these requirements together. Our key contribution is a bargaining architecture that addresses all of the requirements we have identified. The definition of the architecture includes a logical view that identifies the key architectural elements and their interactions, a process view that identifies how the architectural elements can be grouped together into processes, a development view that includes a software framework that provides a reference implementation developers can use to build their own negotiation systems, and a scenarios view by means of which the architecture is illustrated and validated.

SALMonADA: a platform for monitoring and explaining violations of WS-agreement-compliant documents

Quality assurance techniques have been developed to supervise the service quality (QoS) agreed between service-based systems (SBSs) consumers and providers. Such QoS is usually included in service level agreements (SLAs) and thus, SLA monitoring platforms have been developed supporting violation detection. However, just a few of them provide explanation of the violations caused by observed QoS at monitoring time, but not in an user-friendly format. Therefore, we propose a general monitoring and analysis conceptual reference model and we instantiated it with SALMonADA, a SBS that notifies the clients with violations and their causes in their own easy-to-understand specification terms. In addition, our platform performs an early analysis notification that avoids delays in the client notification time when a violation takes place. Moreover, we have implemented a web application as a SALMonADA client, to prove how it monitors, analyses and reports to their clients the service level fulfillment of real services subject to a SLA specified with WS-Agreement.

A Model-Driven Architecture Approach for Modeling, Specifying and Deploying Policies in Autonomous and Autonomic Systems

Autonomic computing (AC), self-management based on high level guidance from humans, is increasingly gaining momentum as the way forward in designing reliable systems that hide complexity and conquer IT management costs. Effectively, AC may be viewed as policy-based self-management. The model driven architecture (MDA) approach focuses on building models that can be transformed into code in an automatic manner. In this paper, we look at ways to implement policy-based self-management by means of models that can be converted to code using transformations that follow the MDA philosophy. We propose a set of UML-based models to specify autonomic and autonomous features along with the necessary procedures, based on modification and composition of models, to deploy a policy as an executing system

Using templates and linguistic patterns to define process performance indicators

Process performance management (PPM) aims at measuring, monitoring and analysing the performance of business processes (BPs), in order to check the achievement of strategic and operational goals and to support decision-making for their optimisation. PPM is based on process performance indicators (PPIs), so having an appropriate definition of them is crucial. One of the main problems of PPIs definition is to express them in an unambiguous, complete, understandable, traceable and verifiable manner. In practice, PPIs are defined informally – usually in ad hoc, natural language, with its well-known problems – or they are defined from an implementation perspective, hardly understandable to non-technical people. In order to solve this problem, in this article we propose a novel approach to improve the definition of PPIs using templates and linguistic patterns. This approach promotes reuse, reduces both ambiguities and missing information, is understandable to all stakeholders and maintains traceability with the process model. Furthermore, it enables the automated processing of PPI definitions by its straightforward translation into the PPINOT metamodel, allowing the gathering of the required information for their computation as well as the analysis of the relationships between them and with BP elements.