Methods-Time Measurement
MTM (of English. Methods-Time Measurement , also in German operation timing analysis , AAZ ) is a method for analysis of work processes and identification of plan and standard times . It is the most frequently used “ system of predetermined times ” in work studies .
history
Originally around 1910 , the American Frank Bunker Gilbreth dealt with the subject of human movement . Asa B. Segur then succeeds in assigning the Gilbreth Therbligs time values. This allows motion sequences to be assessed quantitatively. In 1926 Segur published his work under the title "Motion Time Analysis" (MTA).
Herold Bright Maynard worked on the basics of the MTM with John Schwab and Gustave Stegemerten until 1940 . Maynard finally founded the US MTM Association for Standards and Research in New York in 1951, to which the three transferred the rights. It was first used systematically in the industry of European countries around 1950 in Sweden and in 1957 with the establishment of the Swiss MTM Association in Switzerland. In 1962 the German MTM Association was founded.
Application area
MTM is used - mainly in the industrial environment - to plan manual work processes. For mass production in particular , it is important to determine during the planning phase how long a person needs for certain activities.
MTM finds its justification in planning processes in particular, since all that is required to create an analysis is knowledge of the structure of the work system and an idea of the planned workflow. In contrast to time recording using a stopwatch, it is not necessary to find an existing process to use the MTM method.
method
When using MTM, all movements performed by humans are traced back to certain basic movements for which the required time is known. The smallest movement elements are recorded in MTM-1 , which divides the workflow into movement elements such as "reaching", "grasping", "bringing", "joining", "letting go", supplemented by movement elements such as "walking", "bending / bending over" , "Visual control" etc. divided. For these basic movement elements, empirically determined times with the help of slow-motion recordings are stored in tables , mostly depending on further parameters , such as the distance covered with the movement. At MTM-1 they are mnemonically coded in English (for example “R” for Reach).
Another advantage of the MTM can be found here: the globally standardized coding of the movement elements makes it possible to generate an analysis that can be read and understood by appropriately trained employees around the world. In this way, uniform procedures and methods can be implemented in a company, which on the one hand make uniform quality standards and on the other hand comparable efforts quantifiable.
It is assumed that the time determined by MTM corresponds to that which can be achieved by an average, experienced employee over a whole working day. This corresponds to a performance level of 100%. Depending on the personal performance of the employee, however, up to 130% can be achieved.
The time unit used in MTM analyzes is the Time Measurement Unit . 1 TMU is 0.036 seconds, so 100,000 TMU is one hour.
Condensed procedures for simplified application
Building on MTM-1, there are condensed processes that combine the basic movement elements from MTM-1 in a first step (for example “pick up and place”, which is made up of “reaching, gripping, bringing, joining and releasing” a part) and thus enables a fast and often sufficiently precise analysis of work processes.
In addition to the summary of movement elements, data is systematically compressed in this method so that on the one hand the two-hand analysis practiced in MTM-1 (left and right hands are analyzed separately according to fixed rules) and on the other hand the accuracy of parameters such as gripping distance and joining accuracy a minimum can be broken down.
With these higher-level methods, the duration of more complex work processes can be determined relatively quickly, whereby the accuracy of the system only receives sufficient statistical protection from a certain analysis scope due to the larger and perhaps not always exactly matching components. This results from the compensation of the individual errors according to Gaussian error compensation law, according to which the total error is less than the sum of the individual errors.
Commonly used systems of this type are available under the designations UAS ( U niverselles A nalysier- S ystem) for series production and MEK ( M TM in the E inzel- and K leinserienfertigung) are known.
Based on these condensed procedures, there are tables with pre-analyzed processes for typical assembly activities such as “screwing”, “assembling standard parts” etc.
In addition to weighted methods for a procedure, these also contain standardized process times for activities that cannot be influenced or static holding work.
Using the value tables that have already been condensed by the MTM company, users usually create additional compression levels to map company-specific processes, which enable the user to analyze their own processes in a simplified manner.
MTM is not only used in planning, but also to evaluate existing workplaces. The duration of the activity determined by MTM can be used, for example, as a basis for a performance remuneration such as piecework .
As an alternative to the consolidation, the analysis effort can be reduced by computer-aided working methods, with simplified documentation of the actions or of comprehensive project data being possible at the same time; for example TiCon4 from the German MTM Society or ILMOPLAN (interactive layout and assembly planning).
Requirements for the user
Correct application of the MTM method requires the selection of the correct procedure, which is preceded by a precise examination of the so-called method level in the work system.
In addition to considering the repetition frequency of individual tasks, this includes the degree of organization in the work system as well as the occurrence of process times and static holding work that cannot be analyzed directly with the MTM method. Where there are limits to the MTM process, analyzes can be supplemented by data from other processes, such as time studies (e.g. according to REFA ), machine data sheets , comparisons and estimates, etc.
Last but not least, the user is only able to use the procedures correctly after extensive training, since the user has to practice on numerous examples in order to obtain results that are comparable and reproducible. Ultimately, a precise description of the workflow is required for a correct analysis. Ideally, two people who analyze the same activity using the MTM should get the same result.
literature
- Harold Bright Maynard, Gustave J. Stegemerten, John L. Schwab: Methods-time measurement. McGraw-Hill, New York 1948.
- Rainer Bokranz, Kurt Landau: Handbook Industrial Engineering. Productivity management with MTM. Volume 1: Concept, Volume 2: Application. 2nd Edition. Schäffer-Poeschel, Stuttgart 2012. ISBN 978-3-7910-2863-7 .
- Rainer Bokranz, Kurt Landau: Productivity management of work systems: MTM manual. Schäffer-Poeschel, Stuttgart 2006. ISBN 3-7910-2133-8 .
- Bernd Britzke: MTM in a globalized economy: systematically design and optimize work processes. mi-Fachverlag, Munich 2010. ISBN 978-3-86880-091-3 .
- Wolfgang Holle: Computer-aided assembly planning - assembly planning and simultaneous engineering. Hanser, Munich Vienna 2002. ISBN 3-446-21986-2 .
See also
supporting documents
- ↑ a b German MTM Association e. V. (Ed.): MTM - Right from the start. In: MTM homepage ( Memento of the original from July 31, 2012 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. , read: December 21, 2011
- ↑ Holle, Wolfgang: Computer-aided assembly planning - assembly planning and simultaneous engineering. Hanser, Munich Vienna 2002. ISBN 3-446-21986-2 .
