William C. Perkins

Spatial decision support systems: an overview of technology and a test of efficacy

Abstract A laboratory experiment was used to investigate the effects on decision-maker performance of using geographic information system (GIS) technology as a spatial decision support system (SDSS). GIS are increasingly being used for decision-making, yet research about their contributions to the performance of decision-makers has been lacking. This study makes a contribution to that apparent void. Volunteer subjects completed a site location task that required decisions to be made based upon spatially referenced information. Performance was operationalized as elapsed time and accuracy. The task environment was manipulated in two dimensions. In one dimension, task complexity was varied on two levels. In the other dimension, some subjects were provided a geographic information system as a decision aid; the rest were not. Significant differences were found between task solutions developed by SDSS users and those developed by non-SDSS users. SDSS users experienced shorter solution times and fewer errors for both levels of task complexity. The study builds upon and extends image theory as a basis for explaining efficiency differences resulting from different graphical displays of spatial information.

Stochastic unpaced line design: Review and further experimental results

Abstract Previous design studies of unpaced assembly lines that exhibit stochastic task times indicate that an unbalanced allocation of task times results in optimal output rates. In this article, we present a comprehensive review of the previous literature on this topic and discuss the results of simulation experiments that test the bowl distribution for unbalancing unpaced lines. The simulation experiment was designed to test the bowl distribution in more realistic environments than previously tested and illustrates that a balanced line configuration is as good as or better than an unbalanced line configuration when task times are modeled with more typical values of variance. Stochastic unpaced assembly line research employs both simulation and analytical approaches to test the allocation of buffer capacity and task times to work stations. Analytical models are utilized to investigate simple line designs with exponential or Erlang task time distributions. Simulation is used for longer lines and for normal task time distributions. From the review of the previous research using both approaches, we note five major findings: 1) unbalancing task time allocation is optimal when task time variation is large; 2) unbalanced allocation of buffer storage capacity improves line output rate when task time variation is large; 3) output rate of an unpaced line decreases as the number of sequential workstations increases; 4) output rate increases as more buffer storage capacity is available; and 5) output rate decreases as the task time variation increases. Most of the previous research on unpaced lines investigated lines with few workstations and large task time variation. Empirical research by Dudley (6) suggests that variation of task times in practice is much less than variations employed in previous unpaced line studies. We present the results from simulation experiments that model longer unpaced lines with lower levels of task time variance of the magnitude that is likely to occur in practice. The results of our simulation experiments verify the benefits of using the bowl distribution for task time allocation when line lengths are short and task times experience large variance. However, when line lengths are extended or task time variation is reduced, the use of the bowl distribution for unbalancing the line degrades the lines efficiency. In these situations, the optimal task time allocation is a balanced line. Two important implications for managers follow from the results of our experiments: 1) that unpaced line output rate is relatively insensitive to moderate variations from optimal task time allocations when buffer storage is limited; and 2) that perfectly balanced line designs are optimal for most cases in practice.

An empirical study of an interactive, session-oriented computerized negotiation support system (nss)

Negotiating is one of the four major decisional roles played by managers. In fact, resolving conflict is said to occupy 20% of a managers working hours. This growing frequency of negotiation scenarios coupled with the increasing complexity of the issues which need to be resolved in a negotiation make the possibility of computer enhancement for negotiation very appealing. Implementations of computerized Negotiation Support Systems (NSS) in the business world, international affairs, labor law, and environmental and safety disputes have demonstrated their potential for making negotiation problems more manageable and comprehensible for negotiators. Still, pioneers in NSS research have expressed their dismay at the lack of rigorous empirical research and evaluation of NSS. In particular, research is needed which will determine how and under what circumstances negotiation processes can be enhanced by NSS support.This article describes empirical research on the effects of a highly structured, interactive NSS on the outcome of face-to-face issues resolution and the attitudes of negotiators in both low- and high-conflict situations. In a laboratory experiment, bargaining dyads played the roles of manufacturers negotiating a four-issue, three-year purchase agreement for an engine subcomponent in conditions of high and low conflict of interest. The results of the study showed that NSS support did help bargainers achieve higher joint outcomes and more balanced contracts, but that the NSS support increased negotiation time. Satisfaction was greater for NSS dyads in both conflict levels, and perceived negative climate was reduced in low conflict.One primary implication of the results of this study is that NSS developers should keep in mind the importance of providing users with a system with interactive qualities which not only enhance the decision-making process but also provide them with a sense of participation in reaching the solution, as was done in this study.

Host Country Resource Availability and Information System Control Mechanisms in Multinational Corporations: An Empirical Test of Resource Dependence Theory

The management of the information systems (IS) function is a complex task, particularly in the case of multinational corporations (MNCs), where installations dispersed across distance, time, and cultures can lead to diverse and incompatible systems spreading among foreign subsidiaries. The need to globally control and coordinate the IS management function is often met with resistance from local IS managers, who may perceive corporate standards as intrusive. Resource dependence theory (RDT) argues that control is made easier when a subsidiary unit is dependent on corporate headquarters for critical resources. This study examined the IS management relationship and the use of various mechanisms of control (formal and informal) between 54 headquarters-subsidiary pairs spread across 19 countries of varying resource-richness. While RDT appears to be valid when subsidiaries are dependent on MNC headquarters for resources, the expected relationship between the mechanisms and host country IS resource availability was not observed. Although there was a significant relationship with the use of informal mechanisms and IS resources, it was in the opposite direction to what would be expected by RDT.

The impact of task and cognitive style on decision-making effectiveness using a geographic information system

A laboratory experiment is conducted to investigate how two individual cognitive style factors, field dependence and need-for-cognition, relate to decision-making performance for a spatial task. The intent of the investigation is to establish a methodology for measuring cognitive fit for spatial tasks. The experiment assesses the performance of 142 subjects on a site location task where the problem complexity and availability of a geographic information system are manipulated on two levels. Significant relationships are found for both field dependence and need-forcognition with the two dependent performance variables, solution time and percent error.

Stochastic unpaced line design: A reply

Executive Summary In the May 1985 issue of the Journal of Operations Management, we published a paper containing two major segments ( Smunt and Perkins (1985) ). The first segment provided a comprehensive review of previously published research on unpaced assembly lines. Two of the primary references in this review were path-breaking studies by Hillier and Boling (1966) and Hillier and Boling (1979) . These studies introduced the idea of the “bowl phenomenon,” which suggests that line output can be increased (compared to a balanced line) by unbalancing the line with high service times placed at the beginning and end of the line and low service times placed in the middle of the line. This pair of studies also verified the existence of the bowl phenomenon for exponential and Erlang service times with line lengths up to five stations and buffer capacities between stations from zero to four units. The second segment of our 1985 paper reported on a set of experiments to investigate the “robustness” of the bowl phenomenon under varying service time and buffer capacity assumptions. We tested and confirmed three primary hypotheses: 1. The use of the bowl distribution to unbalance an assembly line will not significantly increase the output rate as compared to a balanced configuration when normally-distributed work station service times are employed with less variance than the exponential distribution. 2. Minimal increases of buffer storage capacity will significantly reduce or will negate the benefit of using the bowl distribution. 3. Output rate is not highly sensitive to moderate variations from optimal task time allocation for stochastic unpaced lines. In other words, we found that the bowl distribution does not have advantages over a balanced line if either more realistic normally-distributed service times are used or larger buffer capacities are available. Thus the bowl phenomenon, while interesting, does not appear to exist in most real world unpaced lines. In the “Note” which immediately precedes this “Reply,” the authors take issue with our conclusions, based primarily on their view that our 1985 experiments were “flawed.” While the “Note” authors provide some valuable arguments and correctly point out a weakness concerning the number of simulation repetitions in our 1985 study, in general it is their arguments that are “flawed,” as we will establish in this paper. In responding to the preceding “Note,” we have conducted a very extensive simulation experiment—much larger than either our 1985 study or the small study conducted as part of the preceding paper. The results of this enhanced study provide strong support for the conclusions of our 1985 paper.

A Comparison of Audio-Conferencing and Computer Conferencing in a Dispersed Negotiation Setting: Efficiency Matters!

The growing globalization of business is making face-to-face communications, decision-making, and negotiations more the exception than the rule. Internet communication in text-only, audio, and video form are all becoming feasible methods of communication between distantly located parties. However, in order for these new technologies to be used most effectively, more investigation is needed into the impact of various media on decision-making, such as that in negotiation. In particular, negotiators need to have a means of choosing the most appropriate communication medium, based on the amount of richness inherent in the medium, for the particular task at hand. This paper presents the results of an empirical study to examine the effectiveness of a computerized negotiation support system (NSS) in supporting bargaining carried out in a dispersed, but synchronous setting. In the study, pairs of college students, using the NSS, participated in a simulated industrial bargaining scenario that tested the impact of communication media employed and level of conflict on contract outcomes and negotiator attitudes. The subjects, located in separate rooms, played the roles of buyer and seller engaged in negotiations either by telephone (audio-conferencing) or Lotus Notes (computer conferencing). In both low and high conflict, the efficiency aspects of audioconferencing — a richer medium in which more communication can take place more quickly — overshadowed any negative social cues transmitted.

Some new factors influencing user information satisfaction: implications for systems professionals

MIS researchers and professionals have identified user information satisfaction as a major objective of information systems development and implementation activities. In the absence of better evaluation criteria, user information satisfaction (or customer satisfaction) is often used as a criterion to evaluate the information systems department. In the MIS literature three major factors have been identified which can influence a users satisfaction with her/his information systems. These factors are: the quality of information products (reports and screens), attitudes towards MIS staff and services, and knowledge and involvement level of user. This paper reports on a pilot study which aims to investigate two additional factors which may be relevant for user information satisfaction. The first additional factor is perceived fairness in the allocation of information systems and related resources to different user groups. Procedural fairness and distributive fairness have been identified as important for an individuals satisfaction in various non-MIS contexts. This study examines the relative role of fairness-related issues in an MIS context as determinants of user information satisfaction. The second factor relates to the impact of information systems design on the work environment of users. Role conflict and role ambiguity in the work environment are explored as a possible factor influencing user information satisfaction.

Performance Metrics: Key to Success in Global Supply Chain Management

ABSTRACT The globalization of business has created new challenges for supply chain management. Many multinational companies have formed partnerships with, and depend on, the cooperation of firms halfway around the world. Managing, controlling, and measuring the performance of global supply chains is growing in complexity, but also in its importance, in order for companies to make a success of their cross-border partnerships. This paper discusses the particular challenges of global supply chain management, the complexity of decisions regarding the location of new facilities, and new information system technologies which facilitate global supply chain management. The paper also presents real-world examples of the successful use of performance metrics to monitor global supply chains and discusses ongoing challenges of global supply chains.