Automated Repair Service Bureau Research Articles

A Highly Distributed Mechanized Loop Testing System

A second generation of the Mechanized Loop Testing System MLT-2 has been developed to extend the mechanized loop testing capabilities of the Bell System Automated Repair Service Bureau to small testing regions and to eliminate the need for manual testing systems such as local test desks, which require high craft skill levels. These objectives have been met using a highly distributed processing architecture, state-of-the-art digital signal processing techniques, and new measurement technology. A typical complex, serving five million lines, may involve the use of nearly 3000 loosely coupled microcomputers. MLT-2 can be deployed as either a standalone system or as an enhancement to its predecessor, MLT-1 In the stand-alone mode, MLT-2 provides both the MLT-1 and local test desk capabilities. In the enhancement mode, MLT-2 provides the local test desk functions and serves as a backup to MLT-1.

Automated Repair Service Bureau: Economic Evaluation

Throughout the conception, development, and deployment of the Automated Repair Service Bureau (ARSB) systems, economic studies have played a continuing and important role. Prior to the development of ARSB, economic studies quantified the potential costs and benefits, leading to the funding of the ARSB project. Throughout the ARSB development phase, the economic studies were refined and used to influence system features. Several field trial evaluations were conducted in Bell Operating Companies (BOCS) to verify the economic models and to refine operational procedures. Prior to system availability, economic planning guides for Loop Maintenance Operations System (LMOS) and Mechanized Loop Testing (MLT) were generated to assist the BOCS in planning for the implementation of ARSB. This article describes the purposes, methods, and results of each of these economic activities. Currently, approximately 75 percent of the Bell System lines are served by LMOS and 50 percent by MLT. Significant reductions in repair expenses, as well as flexibility in the organization of maintenance centers, have been achieved as a result of ARSB development.

Automated Repair Service Bureau: Cable Repair Administrative System

The Cable Repair Administrative System (CRAS) is a recent addition to the Automated Repair Service Bureau (ARSB) that helps extend ARSB usage beyond Repair Service Bureaus into the Outside Plant Maintenance organization. The CRAS system helps this organization to schedule repair forces efficiently and to locate the trouble-prone outside plant facilities that are most in need of rehabilitation. This paper includes an analysis of the unusual features of CRAS, and comments on its development under rapidly changing circumstances.

Automated Repair Service Bureau: Preface

A family of computer-based operations support systems, the Automated Repair Service Bureau (ARSB), has been introduced at Bell Operating Companies. The ARSB includes the Loop Maintenance Operations System and the Mechanized Loop Testing System. A third component, the Loop Cable Maintenance Operations Support System, is in an earlier stage of introduction.

Automated Repair Service Bureau: Two Examples of Human Performance Analysis and Design in Planning the ARSB

Two case studies are described in which human performance methodologies were applied during the development of the Automated Repair Service Bureau (ARSB). The first case study illustrates some of the human performance analysis and design conducted during the specification of the computerized work station that would replace the local test desk in Repair Service Bureaus. The second case study shows how job quality considerations led to improvements in the job of the Repair Service Attendant who receives initial telephone trouble reports from customers. At the same time, a net savings in the time to process the troubles was achieved.

Automated Repair Service Bureau: Evolution

This paper describes the evolution of a family of integrated computer-based operations support systems, the Automated Repair Service Bureau (ARSB). The ARSB supports the maintenance of a telephone customer's service from the local switch to the subscriber's premises (i.e., the loop portion of the service). The automation of labor-intensive manual tasks has made it possible to provide better service at lower cost.

Automated Repair Service Bureau: Mechanized Loop Testing Design

The Mechanized Loop Testing (MLT) system is a functional unit of the Automated Repair Service Bureau (ARSB) which tests and analyzes the condition of customer loops. The test results are used to verify trouble conditions, assist telephone company personnel in providing repair-commitment information to the customer, dispatch the appropriate repair craft, and reduce manual testing requirements. The MLT system design is distributed over three processing levels of the ARSB tree structure (host, front end, controller) to provide the necessary record utilization, data processing, loop analysis, and control of test equipment. The automatic access, monitoring, and testing of loops is performed by specially designed test equipment under the direct control of the controller. The MLT system provides a set of test series, each designed for specific applications. The test series are composed in real time as a function of the equipment thought to be present on the loop and the results of tests already performed to that point in the test sequence. This adaptive testing process has been implemented in hardware and software to provide an effective loop-testing system for most applications in the Bell System.

Automated Repair Service Bureau: Human Performance Design Techniques

Successful implementation of the Automated Repair Service Bureau (ARSB) Systems in the Bell Operating Companies is the result of the early integration of a variety of disciplines in the development process. This paper provides an overview of one of the basic human performance design techniques and an example of its application in the design of the Mechanized Loop Testing System. The expanding role of human performance design in the ARSB systems is also reviewed.

Automated Repair Service Bureau: System Architecture

The four main functions being served by the Automated Repair Service Bureau are (i) Customer Line Card Maintenance — a large, complex data base problem; (ii) Trouble-Taking and Tracking — a simple transaction problem; (iii) Loop Testing — a process-control problem; and (iv) Trouble-History Review — a large, filter, sort, and count report-generation problem. All of these functions were implemented among different computers, which were then networked together to form the full ARSB architecture. This decomposition resulted in an architecture that has been adaptable to Bell Operating Companies' needs over a full decade.

Automated Repair Service Bureau: On-line Documentation: Mechanizing Development, Delivery, and Use

We describe the design and development of on-line documentation for a minicomputer-based management information system. We outline the design choices, compare on-line documents with paper ones, and review human engineering and “software psychology” issues. On-line documents are accessed from any dial-up terminal. Document retrieval shares a common user interface with other information activities like report generation, trouble reporting, and interuser communication. Documents are “modular” with properties that make them easier to create, use, and maintain.

Automated Repair Service Bureau: Second-Generation Mechanized Loop Testing System-A Distributed Microprocessor Application

The Mechanized Loop Testing (MLT) system is that part of the Automated Repair Service Bureau that provides automatic acquisition and analysis of electrical test data for customer telephone loops. The MLT-2 system is a second-generation MLT that has as its basic architectural features communication, loop access, and loop test distributed as closely as possible to the point of testing. Architectural components include a wire center-based Loop Testing System (LTS) and a centrally located Data Communication Network (DCN). Each LTS contains communication, access, and test capabilities, and is logically connected by the DCN to each controlling minicomputer (up to 12). The LTS and DCN are each composed of multiple microprocessor-based circuits. The architecture of MLT-2 is presented. Particular attention is given to the subjects of partitioning both hardware and software, to the development of change-tolerant software, and to intrasystem communication capabilities powerful enough to support a large number of distributed processors. In addition, special measurement techniques employed by MLT-2 that take advantage of analog and digital large-scale integration technology are discussed. Operational scenarios are included for an appreciation of how the MLT-2 system works.