Don E. Malzahn

Methodology to mitigate supplier risk in an aerospace supply chain

Supply chain design is frequently performed from the perspective of a single supplier‐customer relationship. However, as a supplier provides value to different supply chains, it becomes increasingly difficult to optimize each supply chain. Each supply chain has different requirements, procedures, and formats. A member may have requirements placed upon them by one member that contradicts another member. The competitive success of a supplier depends on its ability to participate in different supply chains. This, in turn, affects the competitiveness of each of the other supply chains. This paper presents a generic prescriptive methodology for mitigating risks in an aerospace supply chain and proposes five activities. The methodology provides a mechanism to minimize conflicting objectives. A hypothetical case study is then presented on how the methodology can be applied.

Virtual reality: its usefulness for ergonomic analysis

This paper presents the results of an effort to compare results of an experiment performed in both a virtual and a real environment. The research question addressed is if virtual reality is a suitable tool for performing ergonomic analysis. The subjects performed a palletizing task in the virtual environment and then performed the same task in the real environment. The results showed that VR can be compared to a similar experimental task in the real environment if it involves measuring only range of movements and no velocities or accelerations. This paper presents these results using a lumbar motion monitor and proposes areas for future improvement and research.

Anthropometry of Korean female industrial workers

This paper presents the results of an anthropometric survey conducted on Korean female workers in the garment industry. The data was collected as part of a project to modify work stations that utilized equipment from other countries. A set of 23 body dimensions were taken from a sample of 101 workers (aged 18-28 years). The anthropometric measurements are presented and compared with those of the Western and Japanese female. The results indicate that the body dimensions of the Korean female are different from those of both the Western and the Japanese female. The ratio of sitting height to standing height for the Korean female is closer to that of the Western female than it is the Japanese female.

Task design and modification based on physical ability measurement

Appropriate design and modification of industrial tasks must consider the matching of human physical abilities with task requirements. This paper describes the Available Motions Inventory (AMI) as a testing and evaluation system for measuring human physical ability based on components of manual industrial tasks. Using a microcomputer, one can transform the AMI scores (71 for each hand) into raw scores, ability scores, motion class scores, and performance prediction indices. Examples of task modification strategies using the design-oriented scoring of AMI are illustrated. Also, the reliability of the AMI testing system was evaluated using a multivariate canonical correlation analysis. A high test-retest reliability of 0.85 was obtained.

Techniques of Subjective Assessment: A Comparison of the SWAT and Modified Cooper-Harper Scales:

This study examined two subjective mental workload assessment scales, the Subjective Workload Assessment Technique (SWAT) and the Modified Cooper-Harper (MCH) Scale. The purpose of this study was to make a direct comparison of the two scales in order to determine if both scales were equally sensitive to changes in task difficulty hence, workload. Forty introductory psychology non-aviator students were trained on an aviation like psychomotor dual-task experiment. Task difficulty was manipulated by presenting the subjects with three (low, moderate, high) levels of wind gust disturbance (turbulence) and requiring them to maintain an assigned altitude and airspeed, while responding to a visual choice reaction time secondary task. The data was analyzed using multivariate statistics. The results of the analysis found that both the SWAT and MCH were sensitive to changes in task difficulty. However, the MCH appeared to be less sensitive than the SWAT.

Reducing Customer Wait Time at a Fast Food Restaurant on Campus

In a typical fast food restaurant, the customer expects to receive service quickly. A restaurant manager will want to keep the customers wait time to a minimum. If a customers wait time is higher than their expectation, their satisfaction level will decrease. Most believe that improving a customers wait time will increase operating cost. Therefore, this results in a tradeoff between customers wait time and cost of operation. A study is conducted at a restaurant on the Wichita State University campus to improve its service time. A simulation model is used to analyze the system. A survey is conducted to determine the customers expected wait time. The result of the study is to recommend adding one more server during peak hours to improve customer wait time. An economic cost analysis is also provided to discuss the cost impact of adding one more server.

An ability evaluation system for persons with physical disabilities

Persons with severe physical disabilities are becoming part of the industrial workforce in the United States as mandated by Section 503 of the Rehabilitation Act of 1973. Methods of effective placement and efficient modification of workplaces must be developed if this moral and legal mandate is to be met. This paper describes a system for quantitatively measuring industrially relevant residual motor abilities and a method of efficiently identifying task modification requirements.

A Study of Several Performance Measures of Workers with Carpal Tunnel Syndrome

Objective measures of anthropometry, strength, range-of-motion, muscle activity, and task performance, and subjective ratings of pain were observed in a group of individuals diagnosed with carpal tunnel syndrome (CTS). These measures were compared to a control population showing no symptoms of CTS. Results indicate that individuals with CTS had significantly lower values on some strength tests, less range of motion on several measures, and reduced performance on a simulated task than did the control group. Ratings of pain and distress for the CTS group were also significantly higher than the control group. Occupational and personality factors associated with the CTS group were also identified and discussed.

Evaluating discriminating power of single-criteria and multi-criteria models towards inventory classification

Single-criteria and various multi-criteria models are compared.Models are tested for their ability to classify inventory.Discriminating power test is introduced.Drawback of using single-criteria and R model is captured.Effectiveness of using criteria in descending order is highlighted. Single-criteria and multi-criteria models both are used with regards to inventory classification. In this paper, we evaluated single-criteria and multi-criteria models in terms of their feasibility in classifying inventory items for a given dataset. We introduced discriminating power test. We used two datasets with lead time as the first criterion. We compared the scores of the models. We also modified ZF model and used descending ranking order criteria constraint to address the infeasibilities. Results show that using criteria in descending order reduces the classification infeasibility. Later, we proposed a probability distribution to find the probability of infeasibility for a given dataset against a number of identical scoring items.

Social Learning System: A Reference Model

Abstract This paper is built upon the work of Frank Blackler, Jane Lave and Harry Collins that the fluency in practice language can produce interactive experts. The authors believe the reference model of social learning systems will benefit and shorten the training time to equip novice knowledge managers and researchers with the required knowledge to practice the construction of an effective social learning system. The paper provides a description of social learning systems, a reference model for the activity “Initiate Social Learning System” and the practice language - inputs, constraints, outputs and mechanisms (ICOMs) of the model.