Comprehensive approach to service interaction handling¹

Abstract

To achieve effective and efficient handling of service interactions in an industrial setting, a comprehensive approach is needed. The EURESCOM Project P509, “Handling Service Interactions in the Service Life Cycle”, proposes such an approach providing both technical and organisational solutions to the problem. This novel approach treats interaction handling as a part of service integration rather than service creation. The paper presents the most important elements of the approach: the concept of Interaction Filtering increasing the efficiency of pre-deployment interaction detection; the Service Interaction Handling Process enabling interaction detection on a large scale and providing a framework for interaction solving; new enterprise roles responsible for interaction handling; and a set of off-line and on-line interaction handling mechanisms used by the approach. The evaluation of the mechanisms based on the results of an extensive case study is presented as well.

Introduction

Deregulation of telecom markets and increasing customer demands create new challenges for service providers. They have to promptly react on changing market requirements and provide new services more rapidly than in the past. Though advanced service architectures such as the Intelligent Network (IN) or Telecommunications Information Networking Architecture (TINA) facilitate rapid service provisioning, there are several obstacles in achieving this goal. The service interaction problem is commonly regarded as one of them.

We usually talk about service interaction when the behaviour of one service is affected by the behaviour of another service or another instance of the same service. Interactions can be the reasons of various problems, such as user dissatisfaction, misuse of network resources, deadlocks, etc. They occur mainly because new services and features exceed the original design limitations of the underlying networks, and because new services are developed independently upon different, often inconsistent assumptions. There can be, of course, many other causes of this phenomenon.

Undesired interactions deteriorate the quality of services. Therefore, telecom industry must deal with the interaction problem in one way or another to meet its objectives of speed and quality in the provisioning of new services. Considering the fact that the number of potential interactions grows exponentially with the number of services and their features deployed in a network, finding efficient ways to handle the interaction problem becomes imperative.

Since interactions occur in many forms and can be introduced during nearly every phase of the Service Life Cycle (SLC), interaction handling requires multiple, complementary mechanisms to cover the whole problem. In addition to off-line and on-line mechanisms for interaction detection and resolution, organisational solutions are necessary as well. Interactions do not only have impact on systems, but also on business processes and functions such as customer care, billing, and service management. Therefore, in order to properly handle the interaction problem on an industrial scale a comprehensive approach is needed.

In this paper, we present a proposal of such a comprehensive approach developed by the EURESCOM Project P509 “Handling Service Interactions in the Service Life Cycle”. The approach includes both technical and organisational solutions that are packaged into a new telecom business process. The concept of a new process separates the task of interaction handling form service creation and treats it as a part of service integration, instead.

From the very beginning, EURESCOM has recognised the importance of the interaction problem for the European Public Network Operators⁴ (PNOs). A number of EURESCOM projects such as P103 “Evolution of IN”, P230 “Pan-European IN”, P509 and others addressed different aspects of the service interaction problem.

The EURESCOM Project P509 “Handling Service Interaction in the Service Life Cycle” was entirely devised to the issue of service interaction. The project started in 1995 and ran for two years. P509 was a co-operative work of eight European PNOs: Tele Danmark, Finnet Group, France Telecom, Deutsche Telekom, KPN, OTE, Telefonica, and Telia. P509 was probably the largest international project in the area of service interaction so far.

Results of project P509 including the comprehensive approach to interaction handling have been previously published in EURESCOM internal reports (see 13, 14) as well as in a number of conference papers (see 2, 5, 6, 7, 8, 9, 10, 11, 12). In this paper, we would like to summarise the project's results and highlight the most important elements of the P509 approach.

In the next section, we summarise the state of the art in the field of interaction handling and motivate the directions taken by P509. In the subsequent sections, we present the most important contributions of the P509 approach, such as, the idea of Interaction Filtering; the concept of Service Interaction Handling Process; as well as two new enterprise roles of Service Integrator and Service Mediator responsible for interaction handling. Furthermore, the off-line and on-line mechanisms used by the P509 approach are outlined and evaluated.