Methods Time Measurement Research Articles

Using the Methods-Time Measurement Calculator to Determine the Time Norms for Technological Sewing Operations in the Clothing Industry

Using the Methods-Time Measurement Calculator to Determine the Time Norms for Technological Sewing Operations in the Clothing Industry

Assessing the Suitability of Automation Using the Methods–Time–Measurement Basic System

Due to its high complexity and the varied assembly processes, hybrid assembly systems characterized by human–robot collaboration (HRC) are meaningful. Suitable use cases must be identified efficiently to ensure cost-effectiveness and successful deployment in the respective assembly systems. This paper presents a method for evaluating the potential of HRC to derive automation suitability based on existing or to-be-collected time data. This should enable a quick and favorable statement to be made about processes, for efficient application in potential analyses. The method is based on the Methods–Time–Measurement Basic System (MTM-1) procedure, widely used in the industry. This ensures good adaptability in an industrial context. It extends existing models and examines how much assembly activities and processes can be optimized by efficiently allocating between humans and robots. In the process model, the assembly processes are subdivided and analyzed with the help of the specified MTM motion time system. The suitability of the individual activities and sub-processes for automation are evaluated based on criteria derived from existing methods. Two four-field matrices were used to interpret and classify the analysis results. The process is assessed using an example product from electrolyzer production, which is currently mainly assembled by hand. To achieve high statement reliability, further work is required to classify the results comprehensively.

Use of MTM, RAV and ZAK Methods in Determining Working Methods and Time Norms in Technological Operations of Sewing Clothes

The paper presents the application of MTM, RAV and ZAK methods in the determination of working methods and time norms for the technological process of sewing. The technological operation of sewing the back sleeve seam on a men’s jacket is used for the study. The paper presents the designed workplace in a real production process. In addition, the appropriate working method and the time norm are determined using the MTM (Method Time Measurement), RAV (determination of sewing time for straight seams) and ZAK (determination of sewing time for curved seams) methods. The aim of the study was to combine the methods for determining different types of time (manual, machine-hand and machine) for performing technological operations and precisely calculate the time norms. For the described methods of determining the production time, computer programs were developed that speed up the calculation of the time norm. If the working method is defined in advance and the characteristics of the sewing machine are known, the time norm for each technological operation can be determined in advance. Based on these calculations, it is possible to determine the total time for the production of clothing in advance and thus to plan and schedule the production process and plan the delivery dates to customers. The results show that the technical equipment of the sewing machine and the working method have an influence on the structure of the technological sewing process. By choosing an appropriate working method, the workload and fatigue of the workers is reduced, as an appropriate number of auxiliary hand sub-operations are used. In this way, the appropriate time required to perform the technological operation is achieved.

A supplementary labor cost model for estimating the fixed capital cost of commercial-scale algae photobioreactors plants

Scaling up algae photobioreactors (PBR) for commercial production presents challenges in estimating fixed capital investment costs, particularly the labor costs associated with installing low-cost equipment. Using fractions of the equipment cost to estimate the installation labor cost does not necessarily provide a representative estimate for the labor cost as the labor required is no longer proportionate to the equipment cost. In this study, we developed a supplementary labor cost model to estimate equipment installation and overhead costs for scaling up algae PBRs using a manufacturing cost estimation approach. The model consists of four main steps: identifying and sequencing all processes, estimating labor time using the Methods-Time Measurement procedure, estimating process time, and calculating the overall labor cost. As a proof-of-concept, a pilot-sized PBR has been adapted from the literature to illustrate how to implement these four steps to estimate the labor cost for the commercial size. The model provides more accurate labor cost for fixed capital cost estimation to supplement existing fixed capital cost estimation methods. The model also provides insights into the main cost drivers in the equipment installation process that can be used for bioreactor redesign and further capital cost reduction.

Assembly Line Optimization Using MTM Time Standard and Simulation Modeling—A Case Study

This study presents an approach to solving the assembly line balancing problem (ALBP) using the Methods-Time Measurement (MTM) time standard and simulation software. ALBP is a common problem in manufacturing where a set of tasks with fixed times must be assigned to a series of sequential workstations in order to minimize the total idle time and reduce the assembly cost per product. This study uses MTM, a widely used production process scheduling method, to create a new time analysis of an assembly process that was previously balanced using the Work-Factor method and time study. This literature review shows that there are a lack of combinations of updated time analyses with newer simulation approaches in the current literature, and this was the motivation for the present work. An assembly line simulation was performed using Simio software to evaluate different design options and operating scenarios. The results show that the use of MTM and simulation can help minimize idle time and improve assembly line performance, thereby reducing costs and increasing efficiency. This study shows that the approach of using MTM and simulation is effective in solving ALBP and is a useful tool for manufacturing companies to improve the performance of their assembly lines and reduce costs.

IMPROVE BUILDING DATABASE ON THE OPERATION PROCESS AND PERFORMANCE TIME FOR SEWING OPERATIONS OF KNITTED GARMENT PRODUCTS

This paper presents the findings of the study of building and completion of a standard database on the operation process and sewing time for 02 typical products from knitted fabrics, namely Polo-Shirt and TShirt. The study process is carried out based on applying MTM (Methods Time measurement) standard time analysis method and predetermined time system GSD (General Sewing Data). In this research, we have inherited the results from previous studies including Classifying the main parts sewing linkages, formulated sewing technology process and theoretical analysis of the process of manipulating sewing of the main parts, linkages of the 02 classical textile products including Polo-Shirt and T-Shirt by MTM standard time analysis method and GSD predetermined time system; The studies work of the group of authors on the experimental research content determines the simultaneous influence of a group of factors: distance to place the sewing element (cm), the rotation angle of the sewing element (˚), the size of the sewing element, the number of element layers involved in the sewing, the light intensity (lux) and the skills of sewing workers (grade worker) to the sewing time of knitting products and research simultaneous influences of a group of technological factors including: seam length (cm) and stitches per centimeter (stitches/cm), experiment on 4 sewing devices such as 1-needle lockstitch machine, overlock machine (1 needle and 3 threads) and (2 needles and 4 threads), coverstitch machine (2 needles and 3 threads); and with 3 kinds of single jersey fabrics, which are thin, medium, and thick fabrics to sewing time on the machine of Polo-Shirt and T-Shirt products. The above research results show that there is a big difference between the actual values and theoretically calculated values according to MTM method, GSD predetermined time system, the authors have determined a set of adjustment coefficients for the former and the latter for two values of sewing preparation operation time and sewing time on the machine. We have tested the above research results in 03 enterprises: Hanoi Star Fashion Co., Ltd., Tinh Loi Garment Company and Ha Nam Hanosimex Company Limited and received a lot of practical comments from businesses.

Databases for Estimating Task Element Times: An Overview

This article summarizes several databases (aka predetermined time systems) that provide estimated times for task elements (e.g., reach, move a mouse, make a specific decision, make a specific movement) which can be summed to estimate total task time. Databases emphasized include Methods Time Measurement (MTM), Work Factor, the Keystroke-Level Model (KLM), MODAPTS, Society of Automotive Engineers (SAE) Recommended Practice J2365, and the Touchless Hand-Gesture-Level Model. Databases identified were drawn from industrial engineering, human-computer interaction, automotive interfaces, and other sources. In several cases, example element times and tables from these databases are provided to help readers appreciate and understand their content and structure. Also provided are 6 recommendations (e.g., choose the database that meets the analysis accuracy and time requirements; don’t mix databases with and without mental elements or those with different levels of resolution) to guide readers in database selection.

AUTOMATION OF AN ASSEMBLY SYSTEM USING A ROBOTIC ARM WITH PREDETERMINED TIME METHOD

ABSTRACT: In this study, the automation of an assembly process using a collaborative robotic arm (Cobot) was analyzed. The manual process is the assembly of a Lego® bricks structure and was analyzed using the technique of predetermined movements MTM-1. Moves were defined and processing time was set. The results obtained show that the automated process can increase production capacity by up to 40% using the same personnel as the manual process, but in different shifts. Likewise, defects due to a bad union between the edges of the bricks, which is the main problem in the manual process, are avoided. Finally, the automation process was detailed by associating the manual movements with the Cobot® commands in the simulation environment of the PolyScope Robot User Interface®. What has application to automate other types of manufacturing sequences and manual assemblies. Keywords: Automatization, Robotic arm; Methods-Time Measurement; Cobot®; Lego® bricks.

A Methods-Time-Measurement based Approach to enable Action Recognition for Multi-Variant Assembly in Human-Robot Collaboration

Action Recognition (AR) has become a popular approach to ensure efficient and safe Human-Robot Collaboration. Current research approaches are mostly optimized for specific assembly processes and settings. This paper introduces a novel approach to extend the field of AR to multi-variant assembly processes. The approach is based on generalized action primitives derived from Methods-Time-Measurement (MTM) analysis that are detected by an AR system using skeletal data. Subsequently a search algorithm combines the information from AR and MTM to provide an estimate of the assembly progress. One possible implementation is shown in a proof of concept and results as well as future work are discussed.

Application of methods-time measurement as a tool to improve productivity in a beauty salon

Application of methods-time measurement as a tool to improve productivity in a beauty salon

PERBAIKAN SISTEM KERJA PADA DIVISI PACKING PRODUK RACK TROLLEY DENGAN METHOD TIME MEASUREMENT (MTM)

The work system is the most important thing in the company, especially in manufacturing companies that produce various kinds of kitchen utensils made from stainless steel 402 and stainless steel 201 according to market demand. Of the many existing products, there are products with the highest demand level but take a long time in the packing division, which only has one station. The MTM (Method Time Measurement) method is used to map work movements that focus on work elements in the packing division with mobile gastronomic rack trolley observation products. After observing and measuring, this division has two light work elements but the processing time is quite long, the sandpaper work element is 9.48 minutes with the clean lab work element 8.13 minutes so that in total there are 9 work elements with a time of 53 minutes, by combining the sandpaper and lab work elements. clean with rework mapping, the result is 9.97 minutes and there is a balance of workload between right-hand movement and left-hand movement, from combining these elements, the work element in the packing division becomes more maximal, namely 8 work elements with 37 minutes per product.

Hand Gesture Recognition of Methods-Time Measurement-1 Motions in Manual Assembly Tasks Using Graph Convolutional Networks

ABSTARCT Gesture recognition is gaining popularity in many fields, including gesture control, robotics, or medical applications. However, the technology is barely used in industrial manufacturing processes due to high costs, a time-consuming configuration, and changes in the workflow. This paper proposes a minimally invasive approach to recognize workers' hand motions in manual assembly tasks. The novelty of this approach is the use of only one camera instead of any other sensors and the application of state-of-the-art graph neural networks. The method relies on monocular RGB video data to predict the basic motions of the industry standard motion-time system Methods-Time Measurement-1. Our two-stage neural network composed of hand key point extraction and adaptive graph convolution delivers accurate classification results in real-time. To train and validate the model, we created a dataset containing 22,000 frames of real-world assembly tasks. The data produced by this method in a production line can be used for motion time verification, assembly-line design, or assembly cost estimation. In a use-case study, we show that the proposed approach can generate Methods-Time Measurement analysis tables. These have so far only been accurately created by human experts. Source code: https://github.com/alexriedel1/Hand-Gesture-Recognition-in-manual-assembly-tasks-using-GCN

A VR-based approach in conducting MTM for manual workplaces

Due to current trends in the manufacturing industry, such as mass customization, manual operations contribute drastically to the overall costs of a product. Methods-Time-Measurement (MTM) identifies the optimization potential of manual workplaces, which significantly influences a worker’s productivity. However, traditional MTM requires great efforts to observe and transcribe manual assembly processes. Yet, various digital approaches exist that facilitate MTM analyses. While most of these approaches require the existence of real workplaces or cardboard mock-ups, it would be beneficial to conduct a virtual MTM in earlier phases of production planning. However, the quality of virtual MTM analyses compared to traditional MTM conducted in reality has not been assessed yet. This paper is addressing it by conducting a comparative user study with 21 participants completing the same task both at a real and virtual workplace, which they access via virtual reality technology. Our results show that participants’ MTM-2 values achieved at the VR workplace are comparable to those at the real workplace. However, time study data reveals that participants moved considerably slower in VR and thus needed more time to accomplish the task. Consequently, for the measurement of manual work in VR, it is even necessary to utilize predetermined times, such as MTM-2 since time study data is insufficient. This paper also serves as a proof of concept for future studies, investigating automated transcription systems that would further decrease the efforts conducting MTM analyses.

Computer assisted ergonomic assembly cell design

When designing or modifying an assembly cell, the question at hand is "What will it cost, and what will we gain"? This research features the evaluation of assembly cell variants, taking operator timing and ergonomics into account. For each assembly step requiring an operator e.g. using a screwdriver, the ergonomic score is evaluated by considering the (automatically generated) poses of the operator at the start and finish of each assembly action. Furthermore, throughput is estimated by applying Methods-Time Measurement (MTM) to an inverted kinematics model of a virtual operator. We present our findings on an industrial use case: the assembly of a 15 kg compressor. Starting from an existing cobot cell, alternative assembly cells, with an adjusted resource allocation and a modified cell layout, are evaluated. Besides the performance metrics, human design factors, that are hard to model mathematically, can be incorporated in the design by visualizing and experiencing the work cell in virtual reality. This allows to further fine-tune the cell design.

Automating the process of method-time-measurement

PurposeThis work reports on a developing method time measurement system for measuring manufacturing and assembly processes automatically. This automatic system enables the production engineers and management to detect, process, and display concise and accurate information about the operations in real time.Design/methodology/approachThis system is based on Internet of things technology and RFID-antenna. This methodology consists of seven main steps and one final optimization step. Mainly, the operator is equipped by RFID reader, and the work station tools and devices are provided by RFID tags. Responding the RFID tags to the reader will refer to the certain operations, the difference time between start and end of the operations will be collected immediately and calculated by the microprocessor of the system.FindingsThis automatic system is promising, considering the accurate time measurements and recommendations that obtained from the case study which includes measuring manual assembly operations to be followed in order to overcome the limitations which are not only technical but also managerial, legal and organizational.Research limitations/implicationsThe acquired data about timing and duration of individual operations are anonymized to guarantee the compliance with respect to the privacy laws (GDPR and Italian work's laws).Originality/valueThis work presents a unique system to measure the time instead of traditional methods in the factories environment and satisfies the requirements to study the recommendations in order to overcome the challenges.

Determination of Working Methods and Normal Times of Technological Sewing Operation using MTM System

Working processes in the technological sewing process are performed on machine systems characterized by machine-manual work, where the worker and the machine work simultaneously. Such a work system requires a great deal of responsibility in terms of quality, quantity, and the accurate and timely execution of tasks, which requires the quick and accurate response and extremely good psychomotor and visual skills of workers. This paper presents the process of determining the working method and normal times for the technological operation of runstitching women’s blouse collars, which includes the design of an ergonomically designed workplace, the selection and technical equipment of the universal sewing machine and the determination of the optimal work method and normal times using the Methods-Time Measurement (MTM) system. The research results obtained indicate that the technical equipment of a universal sewing machine has a significant impact on the structure of the technological sewing operation and the working method, i.e. the number of auxiliary manual technological suboperations. Improving technical equipment, i.e. increasing the number of automated functions used on a universal sewing machine, reduces the number of auxiliary manual suboperations, reduces the time required to perform the technological operation and increases work productivity.

COMBINED APPLICATION PROPOSAL OF VALUE STREAM MAPPING (VSM) AND METHODS TIME MEASUREMENT UNIVERSAL ANALYSIS SYSTEM (MTM-UAS) METHODS IN TEXTILE INDUSTRY

Due to high customer expectations in textile world, companies make great efforts in order to survive. Customers always expect best quality, best price and fastest service time. In this article, the method of VSM (Value Stream Mapping) was used together with MTM-UAS (Methods Time Measurement Universal Analysis System) in the production process of the textile industry. The lean manufacturing system, which is developed to provide optimal service to customers, aims both to eliminate wastes in the process and to reduce the time to minimum including time between delivering and the product design stage. Within the scope of this study, the duration of lead time is reduced by eliminating non value added activities in the flow of process with value stream mapping method which is one of the lean manufacturing tools. In order to accomplish requested sustainability of well-disposed standard procedures, it is preferred to use MTM-UAS methodology in this study. An optimal operational procedure is recreated with the aid of MTM-UAS to standardize human body movements. In consequence of the study, production lead time was reduced, recovery at duration of value-added activities were observed, actual body movements were standardized and unnecessary and extra movements were eliminated by using value stream mapping tool and MTM-UAS in textile industry. As a result, it is observed that production lead time was reduced at the rate of %60 and also, duration of non-value-added activities was improved at the rate of 60%.

Szerelési folyamatok hatékonyságának javítása MTM módszerrel

A folyamatosan változó és növekvő kereslet csökkenti a termékek piacra jutásának idejét, így a termelési rendszer rendkívüli kihívásokkal néz szembe. Fontos feladat ezért, hogy a mérnökök pontosan megtervezzék a szerelési folyamatot, amelyhez segítséget nyújtanak az MTM-módszerek. A tanulmány célja az MTM (Methods Time Measurement) elemző módszer bemutatása, amely a munkafolyamatot alapmozdulatokra bontja, és a mozdulatokhoz meghatározott időértékeket rendel. Az alapvető elképzelés a módszer alkalmazása során az, hogy ha a munkafolyamatot a lehető legkisebb részegységekre bontjuk, ezek időszükséglete az egyéntől nem, csak az alkalmazott módszertől függ. Ennek segítségével a munkafolyamat akár elméletben még a tényleges gyártás előtt leírható, és lehetőség nyílik a folyamatos javításra, fejlesztésre. A módszer használatával egy adott szerelési munkafolyamatot fejlesztettünk, amely a cikkben egy esettanulmányon keresztül bemutatásra is kerül.

Assessment of Handover Prediction Models in Estimation of Cycle Times for Manual Assembly Tasks in a Human–Robot Collaborative Environment

The accuracy and fluency of a handover task affects the work efficiency of human–robot collaboration. A precise and proactive estimation of handover time points by robots when handing over assembly parts to humans can minimize waiting times and maximize efficiency. This study investigated and compared the cycle time, waiting time, and operators’ subjective preference of a human–robot collaborative assembly task when three handover prediction models were applied: traditional method-time measurement (MTM), Kalman filter, and trigger sensor approaches. The scenarios of a general repetitive assembly task and repetitive assembly under a learning curve were investigated. The results revealed that both the Kalman filter prediction model and the trigger sensor method were superior to the MTM fixed-time model in both scenarios in terms of cycle time and subjective preference. The Kalman filter prediction model could adjust the handover timing according to the operator’s current speed and reduce the waiting time of the robot and operator, thereby improving the subjective preference of the operator. Moreover, the trigger sensor method’s inherent flexibility concerning random single interruptions on the operator’s side earned it the highest scores in the satisfaction assessment.

Task scheduling method for HRC workplaces based on capabilities and execution time assumptions for robots

With human-robot collaborations, companies are struggling to decide how to schedule tasks in an effective way. We propose an approach to find an eligible division of tasks that forgoes expert knowledge and simulations. Based on a recreation of the application using predefined basic processes and knowledge of the process constraints, the human and robot capabilities are examined. In addition, a time assumption inspired by the Methods-Time Measurement is carried out, to determine the subprocess times. Subsequently, a genetic algorithm assigns the tasks to the human and robot. Expert evaluation and real implementation prove the effectiveness of the proposed approach.