Michael Kraxner

Adding quality-awareness to evaluate migration web-services and remote emulation for digital preservation

Digital libraries are increasingly relying on distributed services to support increasingly complex tasks such as retrieval or preservation. While there is a growing body of services for migrating digital objects into safer formats to ensure their long-term accessability, the quality of these services is often unknown. Moreover, emulation as the major alternative preservation strategy is often neglected due to the complex setup procedures that are necessary for testing emulation. However, thorough evaluation of the complete set of potential strategies in a quantified and repeatable way is considered of vital importance for trustworthy decision making in digital preservation planning. This paper presents a preservation action monitoring infrastructure that combines provider-side service instrumentation and quality measurement of migration web services with remote access to emulation. Tools are monitored during execution, and both their runtime characteristics and the quality of their results are measured transparently. We present the architecture of the presented framework and discuss results from experiments on migration and emulation services.

Improving Decision Support for Software Component Selection through Systematic Cross-Referencing and Analysis of Multiple Decision Criteria

This article discusses opportunities for leveraging scale in cases of recurring scenarios of comparable decisions with multiple objectives in well-defined domains. Based on a software component ranking and selection method that uses utility analysis to separate objective information gathering and subjective assessment, we discuss challenges of decision making such as criterion complexity and evaluation effort. We show that by systematically identifying criteria across cases, it becomes feasible to employ cross-referencing and quantitative assessment of decision criteria and criteria sets across scenarios and organizations to improve decision making efficiency and effectiveness. We present a method and tool that allows referencing decision criteria across cases and employs a set of impact factors for decision criteria and sets of criteria. We discuss the results of analyzing a series of real-world case studies in software component selection. We analyze the applications and implications of the method and its potential to improve decision making effectiveness and efficiency.

An Extensible Monitoring Framework for Measuring and Evaluating Tool Performance in a Service-Oriented Architecture

The lack of QoS attributes and their values is still one of the fundamental drawbacks of web service technology. Most approaches for modelling and monitoring QoS and web service performance focus either on client-side measurement and feedback of QoS attributes, or on ranking and discovery, developing extensions of the standard web service discovery models. However, in many cases, provider-side measurement can be of great additional value to aid the evaluation and selection of services and underlying implementations. We present a generic architecture and reference implementation for non-invasive provider-side instrumentation of data-processing tools exposed as QoS-aware web services, where real-time quality information is obtained through an extensible monitoring framework. In this architecture, dynamically configurable execution engines measure QoS attributes and instrument the corresponding web services on the provider side. We demonstrate the application of this framework to the task of performance monitoring of a variety of applications on different platforms, thus enriching the services with real-time QoS information, which is accumulated in an experience base.

Distributed Preservation Services: Integrating Planning and Actions

Digital preservation has turned into an active field of research. The most prominent approaches today are migration and emulation; especially considering migration, a range of working tools is available, each with specific strengths and weaknesses. The decision process on which actions to take to preserve a given set of digital objects for future access, i.e., preservation planning, is usually an ad-hoc procedure with little tool support and even less support for automation. This paper presents the integration of tools and services for object migration and characterization through a service oriented architecture into a planning tool called Plato, thus creating a distributed and highly automated preservation planning environment.

Plato: A Preservation Planning Tool Integrating Preservation Action Services

The creation of a concrete plan for preserving a collection of digital objects of a specific institution necessitates the evaluation of available solutions against clearly defined and measurable criteria. This process is called preservation planning and aids in the decision making process to find the most suitable preservation strategy considering the institutions requirements, the planning context and available actions applicable to the objects contained in the repository. Performed manually, this evaluation promises to be hard and tedious work, inasmuch as there exist numerous potential preservation action tools of different quality. In this demonstration, we present Plato [4], an interactive software tool aimed at creating preservation plans.

Plato: a preservation planning tool

Creating a concrete plan for preserving an institutions collection of digital objects requires the evaluation of available solutions against clearly defined and measurable criteria. Preservation planning aids in this decision making process to find the best preservation strategy considering the institutions requirements, the planning context and possible actions applicable to the objects contained in the repository. Performed manually, this evaluation of possible solutions against requirements takes a good deal of time and effort. In this demonstration, we present Plato, an interactive software tool aimed at creating preservation plans.