Human Performance of Novice Schedulers for Complex Spaceflight Operations Timelines.

OBJECTIVE: Investigate the effects of scheduling task complexity on human performance for novice schedulers creating spaceflight timelines. BACKGROUND: Future astronauts will be expected to self-schedule, yet will not be experts in creating timelines that meet the complex constraints inherent to spaceflight operations. METHOD: Conducted a within-subjects experiment to evaluate scheduling task performance in terms of scheduling efficiency, effectiveness, workload, and situation awareness while manipulating scheduling task complexity according to the number of constraints and type of constraints. RESULTS: Each participant (n = 15) completed a set of scheduling problems. Results showed main effects of the number of constraints and type of constraint on efficiency, effectiveness, and workload. Significant interactions were observed in situation awareness and workload for certain types of constraints. Results also suggest that a lower number of constraints may be manageable by novice schedulers when compared to scheduling activities without constraints. CONCLUSION: Results suggest that novice schedulers' performance decreases with a high number of constraints, and future scheduling aids may need to target a specific type of constraint. APPLICATION: Knowledge on the effect of scheduling task complexity will help design scheduling systems that will enable self-scheduling for future astronauts. It will also inform other domains that conduct complex scheduling, such as nursing and manufacturing.

The cost of poor sleep: workplace productivity loss and associated costs.

OBJECTIVE: To assess the impact of sleep disturbances on work performance/productivity. METHODS: Employees (N = 4188) at four US corporations were surveyed about sleep patterns and completed the Work Limitations Questionnaire. Respondents were classified into four categories: insomnia, insufficient sleep syndrome, at-risk, and good sleep. Employer costs related to productivity changes were estimated through the Work Limitations Questionnaire. Performance/productivity, safety, and treatment measures were compared using a one-way analysis of variance model. RESULTS: Compared with at-risk and good-sleep groups, insomnia and insufficient sleep syndrome groups had significantly worse productivity, performance, and safety outcomes. The insomnia group had the highest rate of sleep medication use. The other groups were more likely to use nonmedication treatments. Fatigue-related productivity losses were estimated to cost $1967/employee annually. CONCLUSIONS: Sleep disturbances contribute to decreased employee productivity at a high cost to employers.