Ian Robertson

A framework for supporting dynamic systems co-evolution

Abstract Businesses and their supporting software evolve to accommodate the constant revision and re-negotiation of commercial goals, and to intercept the potential of new technology. We have adopted the term co-evolution to describe the concept of the business and the software evolving sympathetically, but at potentially different rates. More generally, we extend co-evolution to accommodate wide-informatics systems, that are assembled from parts that co-evolve with each other and their environment, and whose behavior is potentially emergent. Typically these are long-lived systems in which dynamic co-evolution, whereby a system evolves as part of its own execution in reaction to both expected and unexpected events, is the only feasible option for change. Examples of such systems include continuously running business process models, sensor nets, grid applications, self-adapting/tuning systems, peer-to-peer routing systems, control systems, autonomic systems, and pervasive computing applications. The contribution of this paper comprises: a study of the intrinsic nature of dynamic co-evolving systems; the derivation of a set of intrinsic requirements; a description of a model and a set of technologies, new and extant, to meet these intrinsic requirements; and illustrations of how these technologies may be implemented within an architecture description language (ArchWare ADL) and a conventional programming language (Java). The model and technologies address three topics: structuring for dynamic co-evolution, incremental design, and adapting dynamic co-evolving systems. The combination yields a framework that can describe the system’s specification, the executing software and the reflective evolutionary mechanisms within a single computational domain in which all three may evolve in tandem.

A software architecture approach for structuring autonomic systems

Autonomic systems manage themselves given high-level objectives by their administrators. They utilise feedback from their own execution and their environment to self-adapt in order to satisfy their goals. An important consideration for such systems is a structure which is conducive to self-management. This paper presents a structuring methodology for autonomic systems which explicitly models self-adaptation while separating functionality and evolution. Our contribution is a software architecture-based framework combining an architecture description language based on π-calculus for describing the structure and behaviour of autonomic systems, a development methodology for evolution and mechanisms for feedback and change.

A Support Framework for Dynamic Organizations

This paper describes a framework that is intended to provide an infrastructure for the delivery of support for business processes-including design processes, software development processes and procurement processes. This framework has to be capable of supporting quasi-independent process model instance evolution, and to provide seamless support in this environment for the non-expert Process Manager to exploit this capability.

Process support for evolving active architectures

Long-lived, architecture-based software systems are increasingly important. Effective process support for these systems depends upon recognising their compositional nature and the active role of their architecture in guiding evolutionary development. Current process approaches have difficulty with run-time architecture changes that are not known a priori, and dealing with extant data during system evolution. This paper describes an approach that deals with these issues. It is based on a process-aware architecture description language (ADL), with explicit compose and decompose constructs, and with a hyper-code representation for dealing with extant data and code. An example is given to illustrate the ease-of-use benefits of this approach.

Support for feedback and change in self-adaptive systems

Self-adaptive systems modify their own behaviour in response to stimuli from their operating environments. The major policy considerations for such systems are determining what, when and how adaptations should be carried out. This paper presents mechanisms for feedback and change that support policy decisions for self-adaptation within a computationally complete architecture description language based on the π-calculus. Our contribution is support for feedback through software-encoded probes, gauges and an event distribution network together with support for change through decomposition, reification, reflection, recomposition and hyper-code.

Overcoming Inadequacies in Process Modelling: The Need for Decisioning Be a First-Class Citizen

Process modelling is a way of analysing, describing and enacting the behaviour of processes. A behaviour that process modelling fails to address is that of decision making. Despite the importance of organisational decisions, process modelling languages do not provide any semantics for expressing decision-making aspects such as the identification of alternatives and the handling of uncertainty. This paper proposes an approach, drawing on ideas from decision analysis, to enhance process modelling in the support of decision making. A decision-analysis process model is used to demonstrate the applicability of the approach.

An Implementation of the ISPW-6 Process Example

This paper documents some of the work involved in describing the ISPW-6 process example in terms of graphical models and in terms of a modelling and enactment language PML. It further describes experiences in instantiating this model in ICLs Processwise Integrator support system, and outlines the lessons learnt and directions for future work.

Supporting distributed decision processes using an evolution model

In recent years, emerging Information and Communication Technologies have changed the nature and process of decision making. Decision processes are often distributed, heterogeneous and subject to change. Business process modelling is a key technology for analysing, representing and executing business processes. It can be used to study distributed decision processes and improve decision making practices. A theoretical model of the decision process has been developed in order to better integrate the decision concept with models of business processes. The decision model is executed using a process support system that provides a distributed Web user interface. The enacted decision model evolves as the decision process progresses and supports decision makers if and when needed. The case study of an actual decision process undertaken in a not-for-profit organisation is presented to highlight the use, execution and validation of the decision model.

A Process Support System to Coordinate Societal Decision Processes

Emergent technologies have the potential to broaden democracy by facilitating conventional interactions between electors and authority, but this aim can also be achieved through facilitation of public participation in decision making. This work proposes the use of a framework for engaging local government agencies, stakeholders and citizens in societal decision processes through technology.

Modeling a Support Framework for Dynamic Organizations as a Process Pattern Using UML

This paper describes the motivation of modeling processes as process patterns. The work presented here extends UML modeling into the domain of (meta-) process modeling. It shows, through an example, how (meta-) processes can be modeled as process patterns using collaborations in UML. The structural aspects of a process pattern are modeled using class diagrams and the behavioral aspects are modeled using sequence diagrams. The benefits and shortcomings of modeling processes using patterns are discussed.