Order Selectors Research Articles

Ergonomic improvement using natural language processing for voice‐directed order selection in large industrial settings

AbstractThis field study examined the automatic speech recognition (ASR) of voice‐directed computerized systems for order selectors employed in large industrial settings (e.g., fulfillment centers, distribution centers, warehouses, and manufacturing plants). Voice‐directed systems for order selection require selectors to listen to instructions via a headset and speak into a microphone, directing each worker to select products for store orders throughout the facility. Originally, ASR used voice recognition that required “voice enrollment” (voice setup) for each worker plus a trainer's time required as part of the setup. Voice setup generally averaged about 60 min for both the worker and the trainer. Lately, a newer technology now utilizes “speech recognition,” which eliminates voice enrollment altogether. This study measured order selector voice setup times between voice recognition and speech recognition in five facilities. In two distribution centers where speech recognition was implemented, all voice setup hours for all order selectors (n = 55) plus the trainer's time were eliminated. This amounted to a total savings of 110 h. Moreover, using speech recognition becomes a recurring saving for each new employee entering the organization. Now the focus of training is shifted from voice setup to immediately training workers to select orders via voice, an ergonomic improvement.

The Effects of Computerized Visual Feedback Using Flashing Lights on Order Selection in Large Industrial Settings: Productivity, Accuracy, and Cost Justifications

This report from the field concerns a pilot study that used computerized visual feedback in the form of flashing lights to inform order selectors in an auto parts distribution center to fulfill store orders. Compared to paper pick lists, order selection performance and accuracy reliably increased when the delivery method was the flashing lights. The role of the organizational behavior management participant in industrial settings in designing interventions that increase accuracy and productivity was examined. More than just the intervention, the cost justification was part of the decision-making process about whether to continue with the intervention.

Fractional models for modeling complex linear systems under poor frequency resolution measurements

When modeling a linear system in a parametric way, one needs to deal with (i) model structure selection, (ii) model order selection as well as (iii) an accurate fit of the model. The most popular model structure for linear systems has a rational form which reveals crucial physical information and insight due to the accessibility of poles and zeros. In the model order selection step, one needs to specify the number of poles and zeros in the model. Automated model order selectors like Akaikeʼs Information Criterion (AIC) and the Minimum Description Length (MDL) are popular choices. A large model order in combination with poles and zeros lying closer to each other in frequency than the frequency resolution indicates that the modeled system exhibits some fractional behavior. Classical integer order techniques cannot handle this fractional behavior due to the fact that the poles and zeros are lying to close to each other to be resolvable and not enough data is available for the classical integer order identification procedure. In this paper, we study the use of fractional order poles and zeros and introduce a fully automated algorithm which (i) estimates a large integer order model, (ii) detects the fractional behavior, and (iii) identifies a fractional order system. ► Complexity reduction integer order models. ► Automated fractional order model identification. ► Fractional order model selection. ► Dealing with high order systems. ► Dealing with closely spaced poles and zeros.

Immediate Feedback on Accuracy and Performance: The Effects of Wireless Technology on Food Safety Tracking at a Distribution Center

The effects of wireless ring scanners, which provided immediate auditory and visual feedback, were evaluated to increase the performance and accuracy of order selectors at a meat distribution center. The scanners not only increased performance and accuracy compared to paper pick sheets, but were also instrumental in immediate and accurate data capture and tracking in compliance with the Public Health Security Bioterrorism Preparedness and Response Act (BTA) of 2002. The intervention, which required minimal training, successfully accelerated key operational processes and compliance with food safety mandates. The implications for Organizational Behavior Management practitioners are discussed.

Business Activity Monitoring: Real-Time Group Goals and Feedback Using an Overhead Scoreboard in a Distribution Center

Companies operating large industrial settings often find delivering timely and accurate feedback to employees to be one of the toughest challenges they face in implementing performance management programs. In this report, an overhead scoreboard at a retailer's distribution center informed teams of order selectors as to how many tasks were completed, how many tasks were in queue, and how their team performance measured up against engineered labor standards. Results indicated that group-based immediate feedback can have a substantial impact on performance. Productivity for order selectors (n = 36) assigned to four pick zones increased by an average of 10.25% after intervention. The role of the Organizational Behavior Management experimenter and practitioner in linking business activity monitoring and engineered labor standards in order to accelerate key operational processes was examined.

Replacing Voice Input With Technology That Provided Immediate Visual and Audio Feedback to Reduce Employee Errors

In this report from the field at two auto parts distribution centers, order selectors picked auto accessories (e.g., fuses, oil caps, tool kits) into industrial plastic totes as part of store orders. Accurately identifying all store order totes via the license plate number was a prerequisite for the warehouse management system (WMS) to track each tote to the correct sorting lane, the correct shipping door, the correct route, the correct store, and to invoice the store. Using voice technology, the order selector uttered the license plate number; however, in the event the utterance did not match the license plate number affixed to the lid of the tote, the tote was routed to a “penalty” area of the sorting lanes as a misidentified tote. Each misidentified tote cost the company approximately $500 in lost labor and lost sales. Replacing the utterance of the order selector with a scanning stylus that provided both a “good read” light indicator and a “good read” auditory beep informed the selector that the license plate had been scanned and reliably decreased the number of misidentified totes. The role of the organizational behavior management (OBM) practitioner in industrial settings in designing interventions that increase accuracy and productivity was examined.

The Effects of Computerized Auditory Feedback on Electronic Article Surveillance Tag Placement in an Auto-Parts Distribution Center

ABSTRACT In this report from the field, computerized auditory feedback was used to inform order selectors and order selector auditors in a distribution center to add an electronic article surveillance (EAS) adhesive tag. This was done by programming handheld computers to emit a loud beep for high-priced items upon scanning the item's bar-coded Universal Product Code (UPC). Adding the auditory component to the visual component of the handheld computer significantly decreased the number of untagged EAS items leaving the facility. The role of the organizational behavior management practitioner in applied settings in designing interventions—some of which can be quite simple and inexpensive, yet add tremendous value—was examined.

Comparing the Effectiveness of an Isokinetic Evaluation to a Functional Capacity Evaluation in Reducing Industrial Injuries

1503 PURPOSE: To compare the effectiveness of a functional capacity evaluation (FCE) to an isokinetic physical capability evaluation (PCE) in reducing soft tissue injuries in industry. METHODS: New hire applicants for a national food distribution services company were evaluated from 2/00 – 3/03. From 2/00 – 8/01, each applicant received a FCE (FCE Group) and from 9/01 – 3/03, each applicant received a PCE (PCE Group). The applicants were delivery drivers and order selectors. The FCE group tested and recommended for hire 1,650 individuals and the PCE group tested and recommended for hire 1,900 individuals. The FCE consisted of a traditional work simulation test and a cardiovascular step test. The PCE group received an isokinetic flexion/extension evaluation of the knees and shoulders at 60 degrees/sec. Frequency of injury and cost of injury were monitored and tracked for each group during their respective 19-month period. Only those injuries occurring within the first 19-months of employment were considered. RESULTS: A Chi-Square analysis showed the observed frequency of injury vs. the expected frequency was significantly different. The observed frequency for the PCE group was 24 vs. the expected of 27 compared to the observed frequency for the FCE group of 45 vs. the expected of 21 (Chi-Square = 1552.04, df = 1, p< .0000). The mean total injury cost for the PCE group was significantly less than the FCE group ($5,659 vs. $16,504, Kolmogorov-Smirnov Test, p<.05). CONCLUSION: These results show an isokinetic knee-shoulder new hire physical capability evaluation to be significantly more effective in reducing work related injuries than a traditional FCE.

Comparing the Effectiveness of an Isokinetic Evaluation to a Functional Capacity Evaluation in Reducing Industrial Injuries

1503 PURPOSE: To compare the effectiveness of a functional capacity evaluation (FCE) to an isokinetic physical capability evaluation (PCE) in reducing soft tissue injuries in industry. METHODS: New hire applicants for a national food distribution services company were evaluated from 2/00 – 3/03. From 2/00 – 8/01, each applicant received a FCE (FCE Group) and from 9/01 – 3/03, each applicant received a PCE (PCE Group). The applicants were delivery drivers and order selectors. The FCE group tested and recommended for hire 1,650 individuals and the PCE group tested and recommended for hire 1,900 individuals. The FCE consisted of a traditional work simulation test and a cardiovascular step test. The PCE group received an isokinetic flexion/extension evaluation of the knees and shoulders at 60 degrees/sec. Frequency of injury and cost of injury were monitored and tracked for each group during their respective 19-month period. Only those injuries occurring within the first 19-months of employment were considered. RESULTS: A Chi-Square analysis showed the observed frequency of injury vs. the expected frequency was significantly different. The observed frequency for the PCE group was 24 vs. the expected of 27 compared to the observed frequency for the FCE group of 45 vs. the expected of 21 (Chi-Square = 1552.04, df = 1, p< .0000). The mean total injury cost for the PCE group was significantly less than the FCE group ($5,659 vs. $16,504, Kolmogorov-Smirnov Test, p<.05). CONCLUSION: These results show an isokinetic knee-shoulder new hire physical capability evaluation to be significantly more effective in reducing work related injuries than a traditional FCE.

Test of Significance in order selection

To select a proper order is a critical step in fitting a model to a data set. It is well known that Mallows' Cp,as well as other asymptotically equivalent order selectors, often selects an excessively large order. To reduce the chance of overestimating the optimal order using a heavier penalty term has been suggested. In this paper, the issue about setting the penalty term is considered from a perspective similar to hypothesis testing. It is suggested setting the penalty according to the probabiiity of overestimating the true or optimal order. A test procedure based on the order selecters is proposed to assess the significance of the order selected. Some simulation results are presented to illustrate the properties of the order selectors and the test procedure. The application of the procedures to two real examples are also presented.

Spine loading and probability of low back disorder risk as a function of box location on a pallet

It is widely believed that depalletizing operations in manufacturing and service environments substantially increase the risk of occupationally related low back disorders (LBDs). It has been established that the weight of the box lifted off a pallet can affect the risk of occupationally related LBD but few have considered the influence of the location of the box on the pallet (region) when assessing risk. Thus, the objective of this study was to assess spinal loading characteristics and the probability of high LBD risk as a function of box weight and its location on the pallet. Ten experienced order selectors were recruited from a local distribution center and were evaluated as they transferred boxes of different weights (40, 50, and 60 lb) from six different locations (regions) of a pallet to a pallet jack. Workers were monitored for their trunk motion characteristics as well as the electromyographic (EMG) activity of ten trunk muscles as they performed the task. Workplace factors as well as trunk kinematic and EMG information were used as inputs to: (1) a risk assessment model, and (2) an EMG-assisted model that was used to predict the three-dimensional spine loadings that occurred during the task. The results indicated that conditions where a worker must reach to a low level of the pallet increased spinal load and risk probability far more than changes in the weight of the box. Thus, spinal loads were significantly large in magnitude and would be expected to lead to an increase in low back disorders when workers lifted form the lowest layer of the pallet. The load moment was found to be strongly influenced by pallet region, which resulted in increased spinal loading and risk probability as the moment increased. This effort has also facilitated our understanding as to why spine loading increases under the various conditions studied in this experiment. Nearly all differences in spinal loading can be explained by a corresponding difference in coactivation of the trunk musculature. This in turn significantly increases the synergistic forces supplied by each muscle to the spine and results in an increase in spinal loading. © 1997 John Wiley & Sons, Inc.

The Effects of Box Weight, Size, and Handle Coupling on Spine Loading during Depalletizing Operations

It is widely known that the order selection task in food distribution centers places the worker at risk of occupationally-related low back disorders (LBDs). One approach to controlling this risk consists of manipulating the characteristics of the object or box to be handled in the food distribution center. However, it is currently unknown what effect these changes to the box characteristics would have on the loading of the spine and the subsequent risk of low back disorder. Hence, the objectives of this study were to determine the change in spine loading at L5/S1 associated with selecting boxes that varied as a function of: 1) weight (40, 50, and 60 lbs), 2) size (2681 or 1584 cu. in.), and 3) the existence of handles or hand holds. In addition, these variables were explored as a function of where the box was on a pallet. Ten experienced order selectors were recruited from a local food distribution center and were evaluated as they selected boxes of different characteristics from a slot (bin) on to a pallet jack. Workers were monitored for their trunk motion characteristics as well as the EMG activity of 10 trunk muscles as they performed the task. The kinematic and EMG information was used as inputs to an EMG-assisted model that was used to predict the three-dimensional spine loadings that occurred during the task. The results indicated that conditions where a worker must reach to a low level of the pallet significantly increases spinal load. Thus, spinal loads were significantly great and only of a magnitude that would be expected to lead to low back disorders when workers lifted form the lowest layer of the pallet. Handles had the affect of reducing the spinal loading by an amount that was equivalent to a reduction in box weight of about 10 pounds. This effort has also facilitated our basic understanding as to why spine loading increases under the various conditions studied in this experiment. Nearly all differences in spinal loading can be explained by a corresponding difference in coactivation of the trunk musculature. This in turn significantly increase the synergistic forces supplied by each muscle to the spine and resulted in an increase in spinal loading.

A novel approach to preemployment worker fitness evaluations in a material-handling industry.

Effectiveness of a pre-employment worker fitness evaluation in a sample of grocery warehouse order selectors was studied retrospectively. Implementation of the program began in March 1990 and as of September 10, 1993, 1100 prospective employees have been tested. Identification of prospective employees with the necessary job specific physical requirements was conducted with a standardized test protocol based on job analysis and normative data. Follow-up injury rates and costs for this department were supplied by the company for statistical analysis. To establish normative data for minimum standards of job performance, a control group of current, uninjured and experienced order selectors was evaluated in respect to job requirements and isokinetic variables. In the control group, 17 variables were identified including one each from two 5-minute repetitive lifting tasks with weighted crates and 15 isokinetic trunk function and lifting variables. Prospective employees were required to successfully complete at least 15 variables for hire as an order selector. The t-test for significance of difference between two proportions was used to compare injury rates in 1989 to those reported in 1990, 1991, 1992, and 1993. Statistically significant differences were found between the unimplemented comparison year of 1989 and the 4 years post-implementation. Preliminary data suggests that a worker fitness evaluation using the above methodology may be an effective method of reducing injuries and subsequent costs.

Biomechanical And Ergonomic Stresses In Warehouse Operations

Abstract Biomechanical and ergonomic stresses to the wholesale grocery order selectors were studied in three different warehouses. Biomechanical job evaluation predicts that at least 33% of the male and 75% of the female industrial workers would be overstressed on these jobs. Ergonomic evaluation showed that the racks were either too high or too low. The order selectors are required to lift heavy and bulky loads to a vertical height which is close to the reach limit for most people and at a horizontal distance which is close to the functional reach limit. Biomechanical and ergonomic requirements of the order selectors' jobs are discussed.

A Physiological Evaluation of Time Standards For Warehouse Operations as Set by Traditional Work Measurement Techniques

Abstract This research studied physiological stresses to grocery order selectors. Sixty-three male workers from three different warehouses participated in the study. Oxygen uptake and heart rates were continuously recorded while the subjects performed their routine work. Performance levels of the workers were determined using the traditional work measurement techniques employed by the warehouses. The duration of the observations ranged from 12 to 65 min (mean 34 min) depending upon the size of the order and the pace of the worker. The mean performance levels (allowed time per order/actual time per order ∗ 100) were 119, 111 and 98% and the corresponding mean metabolic rates were 6.2, 6.0 and 8.3 Kcal/min and the mean heart rates were 110, 122, and 133 beats/min in warehouses 1, 2 and 3, respectively. Approximately, 24, 30 and 64% of the male workers failed to meet the 100% performance index in warehouses 1, 2 and 3, respectively, while their average energy expenditure rates were 6.3, 5.4 and 8.4 Kcal/min. There was no significant correlation between the energy expenditure and performance index and the heart rate and performance index. In terms of the physiological cost of work performed, there were inconsistencies within a warehouse and large differences between warehouses. Physiological requirements of the order selector's job are discussed.

Physiological stresses in warehouse operations with special reference to lifting technique and gender: a case study.

A field study was conducted to evaluate the effects of lifting technique (free-style vs. straight-back, bent-knee) on male workers' performances and physiological responses. A secondary objective was to study physiological stresses to female order selectors using the free-style lifting technique only. Six male and six female workers performed their routine work of grocery order selection in three different warehouses while their oxygen uptake and heart rates were measured. Workers' performances were determined using the traditional work measurement techniques (time study, methods time measurement and master standard data systems) employed by the warehouses. Total cases, weight, volume, actual and allowed time for each order were also determined. Statistical analysis showed that the performance levels of the male workers (allowed time per order * 100/actual time per order) were significantly lower and oxygen uptake and heart rates were higher for the straight-back, bent-knee method as compared to the free-style lifting technique. Male workers lifted more cases, weight and volume/min with the free-style lifting technique than with the straight-back, bent-knee method. It is concluded that the traditionally recommended straight-back, bent knee method of lifting is slower and physiologically more demanding. It is practically impossible for a substantial number of workers to meet the existing time or performance standards based on traditional work measurement techniques--when using the straight-back, bent-knee method of lifting recommended by the warehouses.(ABSTRACT TRUNCATED AT 250 WORDS)

Physiological Stresses in Warehouse Operations with Special Reference to Lifting Technique and Gender: a case study

A field study was conducted to evaluate the effects of lifting technique (free-style vs. straight-back, bent-knee) on male workers' performances and physiological responses. A secondary objective was to study physiological stresses to female order selectors using the free-sytle lifting technique only. Six male and six female workers performed their routine work of grocery order selection in three different warehouses while their oxygen uptake and heart rates were measured. Workers' performances were determined using the traditional work measurement techniques (time study, methods time measurement and master standard data systems) employed by the warehouses. Total cases, weight, volume, actual and allowed time for each order were also determined. Statistical analysis showed that the performance levels of the male workers (allowed time per order ★100/actual time per order) were significantly lower and oxygen uptake and heart rates were higher for the straight-back, bent-knee method as compared to the free-style lifting technique. Male workers lifted more cases, weight and volume/ min with the free-style lifting technique than with the straight-back, bent-knee method. It is concluded that the traditionally recommended straight-back, bent knee method of lifting is slower and physiologically more demanding. It is practically impossible for a substantial number of workers to meet the existing time or performance standards based on traditional work measurement techniques — when using the straight-back, bent-knee method of lifting recommended by the warehouses. The average working heart rate and the peak heart rate for female workers were significantly higher than those for male workers while there were no significant differences in performance index, energy expenditure, actual cases, weight and volume lifted/min. The average energy expenditure and heart rate for the male and the female workers were significantly higher than the acceptable limits. Time standards based on traditional work measurement techniques were physiologically unacceptable, especially for female workers.