Assistance - work carried out by one entity in support of another - is a concept of long-standing interest, both as a type of human work common in organizations and as a model of how computational systems might interact with humans. Surprisingly, the perhaps most paradigmatic form of assistance - the work of administrative assistants or secretaries - has received almost no attention. This paper reports on a study of assistants, and their principals and managers, laying out a model of their work, the skills and competencies they need to function effectively, and reflects on implications for the design of systems and organizations.

One of the pervasive challenges facing any software development team is getting the right level and timing of communication to ensure that people are able to coordinate their work effectively. Communication issues are difficult to address because important aspects of communication are largely invisible to both management and the individuals on the team. Communication challenges are further exaggerated in global software teams, because of the different time-zones, cultures, and working environments. Social Network Analysis (SNA) is an established method for revealing patterns of human communication and decision-making. This tutorial introduces students to basic concepts in SNA, illustrates how SNA can be used to understand the dynamics of and address common communication problems in global software teams, and provides structured exercises in data capture, analysis and interpretation.

This paper presents modeling frameworks for distributing development effort among software components to facilitate cost-effective progress toward a system reliability goal. Emphasis on components means that the frameworks can be used, for example, in cleanroom processes and to set certification criteria. The approach, based on reliability allocation, uses the operational profile to quantify the usage environment and a utilization matrix to link usage with system structure. Two approaches for reliability and cost planning are introduced: Reliability-Constrained Cost-Minimization (RCCM) and Budget-Constrained Reliability-Maximization (BCRM). Efficient solutions are presented corresponding to three general functions for measuring cost-to-attain failure intensity. One of the functions is shown to be a generalization of the basic COCOMO form. Planning within budget, adaptation for other cost functions and validation issues are also discussed. Analysis capabilities are illustrated using a software system consisting of 26 developed modules and one procured module. The example also illustrates how to specify a reliability certification level, and minimum purchase price, for the procured module.

This paper addresses the problem of determining a single facility location on an undirected tree with n nodes and edges that fail independently with probability (1 − pe) so that service provided to demand points can be achieved with reliability. Termed the relisum problem, the objective is to find a network location that maximizes the expected number of nodes reachable by operational paths. A decomposition formula is developed for which several properties are analytically derived and realistic vertex optimality conditions are identified. Two polynomial algorithms are presented: an O(n3) algorithm which is an adaptation of the Floyd-Warshall algorithm for finding all pairwise shortest paths in a graph and an O(n2) algorithm based on a depth-first node traversal and the decomposition nature of an operational path. Computational results are provided, and sensitivity analysis ranges and marginal values for pe are analytically derived. Properties and algorithms for the weighted version of the problem are discussed, as well as a polynomial heuristic for finding a relisum node on a cyclic network. © 1996 John Wiley & Sons, Inc.