Mark S. Hoffman

Impact on retail checkout ergonomics of scanner technology evolution and package design

Abstract The design of bar code scanners has steadily improved scanning performances over the past 20 years. Changes in scan patterns, improvements in decode algorithms, and design features of the hardware user interface have resulted in scanners that are ergonomically superior both in biomechanics and overall performance. This study reviewed scanner performance and technological developments, and compare these to changes in checkstand use and the mix of merchandise packages scanned. The results indicate that the impact of future innovations in scanner design to improve throughput and the accuracy of data captured will be minimal. The greatest challenge to improve overall checkout performance is for merchandise suppliers to consider the ergonomics of scanning merchandise based on package design and placement of the bar code. Relevance to industry This work shows the impact of scanner design on cashier productivity in the retail checkout environment. Improvements in the user interface of scanners and the scanner optical recognition logic has shown a dramatic impact on the total percentage of scanned items. Package design and bar code placement is the next area to enhance the ergonomics of scanning.

An Empirical Investigation of Ergonomics in the International Retail Workstations

A study as conducted to assess the impact of the International regulations on throughput in retail checkout workstations using “state-of-the-art” POS (Point Of Sale) equipment. Productivity measures were derived for the various workstation configurations recommended in the German guidelines as well as those designed from empirical sources. A cross-validation of these data to performances from domestic workstations was made to assess the potential impact of similar ergonomic standardization in the United States.

Use of a Secondary Task Methodology for Determining Acceptability of Flat-Panel Display Technologies in Consumer Environments

Flat-panel displays are used in consumer environments for displaying information where limits on content, physical space, power, and cost constraints are critical. Applications have traditionally included Retail Point-of-Service (POS) terminals. Most common flat-panel display technologies found in the consumer markets are Liquid Crystal Displays (LCDs), Plasma, and Vacuum Fluorescent displays. Emitting displays, i.e., Vacuum Fluorescent, Plasma, and LEDs were introduced into the marketplace with few reservations as to their general acceptance since normal ambient lighting conditions other than direct sunlight had minimal impact on readability. However, reflective display technologies, i.e., LCDs have not been widely accepted in POS products because of slower response times and a more restrictive range of ambient light needed to achieve acceptable viewing conditions. Many techniques used for determining the acceptability of a display technology for the POS environment presently used in industry are solely based upon the physical and functional performance characteristics of the display itself. This approach is similar to those used for evaluating video displays in that the primary concern is the stability of the displayed output for the intended user environment. Often these evaluations are conducted in a laboratory and therefore do not compare display performances relative to the intended end user. Even though this approach is cost-effective because the physical attributes of the display can be tailored to maximize readability, it does not consider the effect of the displayed information beyond the properties of the human visual system. Therefore, it would be desirable to develop an experimental methodology for evaluating flat-panel display technologies based upon human information processing capabilities. This requires using the information in cognitive task loadings equivalent to those experienced in the user environment. Studies comparing LCDs and Plasma display technologies were designed to construct a cognitive-perceptual model for usability assessment in the retail POS environment. A secondary task methodology was used to predict mental workload associated with each display. A Choice Reaction Time (CRT) paradigm proved to be an effective method for exploring cognitive-behavioral problems associated with the displays beyond those considered in the traditional methods of display evaluation.

Workstation Design Optimization through a Simulation Model

A man-machine systems simulation model was developed as a cost-effective marketing tool for systems design in the retail sales environment. SAINT (Systems Analysis Integrated Network of Tasks) modeling technique was chosen because of its capabilities to simulate complex human engineering system performances. Tasks performed at the workstations ranged from an automated real-time inventory control device requiring a high degree of man-machine interactivity to social interactions between the operator and customer. Network parameters were defined from performances observed both in laboratory and field tests. The model included the capability to mix and simulate multiple workstations within a given environment. Work surface dimensions, operator ability levels, and processing strategies were manipulated to maximize productivity. This approach to workstation design proved to be an effective method of systematically reducing the number of alternative configurations. It also reduces the requirement of elaborate time-consuming laboratory experiments to verify a proposed design concept. A conversational interface was developed to encourage its utilization by the untrained user.