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Process Excellence
Published in James William Martin, Operational Excellence, 2021
To achieve this takt time, work tasks are broken down into smaller groups of lower-level work tasks as shown in Figure 5.20. To do this, work tasks are studied to find the best way to complete them. Common methods to analyze work tasks are work sampling, micro-motion studies, and predetermined time standards from tables grouped by type of work task. Work sampling studies a work task over a period of time and determines the best way to accomplish it. Micro-motion studies are like work sampling but are more precise in determining task time duration because the tasks are broken down further into micro-motions. Cameras can be used to record each motion so they can be reviewed several times to achieve accurate calculations. Time duration is also measured at a microsecond level of precision. Predetermined time standards are applied up front to a new process design and later validated through work sampling or micro-motion studies. Time standards are used with similar analyses of machine cycle times to balance the flow of work across a process to achieve the required takt time.
The Operations Plan
Published in David C. Kimball, Robert N. Lussier, Entrepreneurship Skills for New Ventures, 2020
David C. Kimball, Robert N. Lussier
Predetermined time standards are determined by using known times for all tasks in a job in order to determine how long it should take to complete it. They are based upon the idea that there are only so many basic motion patterns. Thus, any activity or job would be the result of particular combinations of these motions. After observing many different activities, an analyst can segregate such basic motions as:
Global Supply Chain Engineering Definitions
Published in Erick C. Jones, Supply Chain Engineering and Logistics Handbook, 2020
Time study is used to determine the time required by a qualified and well-trained person working at a normal pace to do a specified task. The difference between motion study and time study is that motion study is largely based on design and time study involves measurement. Standard time for operations is established using time study. Time studies are mostly utilized to establish wage incentives. It is also used to Determine schedules and planning work.Determine standard costs, and as an aid in preparing budgets.Estimate product cost before manufacturing it.Determine machine effectiveness, and as an aid in balancing assembly lines and work done on a conveyor.Determine time standards to be used as a basis for labor cost control.
The Reach and Impact of the Remote Frequency and Time Calibration Services at NIST
Published in NCSLI Measure, 2018
The services reach and impact a wide variety of industrial sectors (Figure 6). The largest customer group consists of in-house calibration laboratories who use the NIST reference to calibrate their primary standard, and then in turn use their primary standard as the reference for calibrations of other equipment. Industries whose in-house calibration laboratories rely on the NIST services include U.S. defense contractors (13%), aerospace (9%), and nuclear energy (2%), in addition to U.S. military installations (13%). Collectively, these in-house calibration laboratories represent 37% of the customer base. The largest industrial sector represented in the customer base consists of manufacturers of electronic test and measurement equipment and instrumentation (26%), which includes manufacturers of frequency and time standards, such as atomic oscillators and GPS disciplined oscillators. These customers require NIST validation of their measurements to ensure that the products they design, manufacture, and sell can meet their desired specifications for frequency and/or time. Private calibration laboratories that sell calibrations to customers outside of their own organizations, and nonmilitary U.S. government laboratories each contribute 8% to the NIST customer total. The customers described in this paragraph are primarily interested in frequency measurements, although many also maintain an accurate time standard.
Reliability-based network flow estimation with day-to-day variation: A model validation on real large-scale urban networks
Published in Journal of Intelligent Transportation Systems, 2018
Mohammad Torkjazi, Parisa Sadat Mirjafari, Hossain Poorzahedy
Measures of travel time reliability and the relationships between them are of interest to FHWA (2006), Higatani, Kitazawa, Tanabe, Suga, Sekhar, and Asakura (2009), Pu (2011), Sekhar et al. (2007), and Saw et al. (2015). The measures introduced in these works include average travel time, 90th or 95th percentile travel time, standard deviation, coefficient of variation, buffer time, buffer index, planning time index, skew statistic, misery index, frequency of congestion, on-time arrival, and others. Pu (2011) examines a number of these measures and explores their mathematical relationships, particularly in light of a log-normal distribution assumption, and finds coefficient of variation a better proxy measure for several other reliability measures. Higatani et al. (2009) analyze the differences and similarities of such reliability measures in an expressway network, as well as the effect of traffic incidents on them.
Research on the control path and countermeasures of net CO2 emissions in central China – represented by Jiangxi Province
Published in Environmental Technology, 2022
In order to determine a reasonable and natural threshold and meet the best time standard [29], referring to the method of Zhou (2021), the consistency threshold is set to 0.8, the case frequency is set to 1, and fsQCA is used to configure the development of net CO2 emissions reduction, and the results are listed in Table 12: