PRINCIPLES AND TECHNIQUES:STANDARD DATA

4. STANDARD DATA

Many operations in a given system have several common elements. The element ‘‘walking,’’ for example, is a component of many different jobs. When these jobs are timed, the same common

element is timed again and again. The function of the analyst would therefore be made much easier if the analyst had a set of data from which he or she could readily derive standard times for these common work elements without necessarily going into the process of timing each one. If, for instance, a standard time would be derived for the particular element ‘‘walking’’ and could be read directly from a table, this would not only reduce effort and cost but also lead to greater consistency in time estimations.

It is however, difficult to visualize a situation where all the possible elements making up a job could be timed and stored for future retrieval. We may therefore conclude that in practice it is better to restrict the number of jobs for which standard data are derived.

The reliability of the data can be increased if as many common elements as possible that are performed in the same way are grouped together from analysis and if a sufficient amount of accu- mulated or collected data on each element has been analyzed by a trained analyst. Making sure that all the factors affecting a certain element have been taken into consideration can further increase reliability.

Standard data refers to all the tabulated elemental standards, curves, alignment charts, and tables that are compiled to allow the measurement of a specific job without the use of a timing device.

These are element time standards, from time studies, that have been proven to be accurate and reliable. There are three levels of detail: MOTION, ELEMENTAL, and TASKS. The more refined the standard data element, the broader is its range of application. Although it has the widest usage, it takes longer to develop.

Motion-level systems are typified by MTM, MODAPTS, or other PTS systems. It involves times of the smallest component range from about 0.01 to 1 sec (e.g., reach, grasp, move, position, release). Elemental level system components vary from about 1 to 1000 sec. Components come from either PTS systems or time study (e.g., get equipment, polish shoes, put equipment away). Task-level component times range upward. Components come from elemental combinations, from time study, from occurrence sampling, or even from employee activity logs (e.g., loading of truck, driving truck 200 km [124 mi], unloading truck).

Components can either be constant or variable. It is critical in developing standard data to model variable components. Example of variable elements are include in Table 16, illustrating the levels of detail for standard time systems (Konz 1990).

The advantages of the standard data approach include the following:

1. Provides a catalog of facts, therefore saving time, effort, and money

2. Permits analysts to concentrate on methods improvement

3. Provides a quick and reliable tool for methods and standards evaluation

4. Allows standards to be determined prior to production

5. Results in more consistent standards among jobs, departments, and plants

6. Eliminates the subjective rating of the operator’s speed performance

4.1. Developing Standard Time Data

The general approach in developing standard time data is as follows:

1. Decide on the coverage: The coverage should be restricted to one or more departments or work areas or to a limited range of processes within the system in which several similar elements, performed by the same method, are involved in carrying out the jobs.

2. Break the jobs into elements: In this case, try to identify as many elements as possible that are common to the various jobs.

3. Decide on the type of reading: Decide whether to use readings based on stopwatch time studies or derived from PTS systems such as MTM.

4. Determine the relevant factors: There are factors that are likely to affect the time for each element. Classify them into major and minor factors.

5. To validate the standard time data, measure the time taken to perform the activity from actual observation.

4.2. Uses of Standard Data

For easy reference, standard data should be classified as either constant or variable data elements. Constant standard data elements should be tabulated. Variable data can either be tabulated or ex- pressed as a curve or equation through formula construction.

Formula construction represents a simplification of standard data. It involves the design of an algebraic expression or a system of curves that establishes a time standard in advance of production by substitution of known values peculiar to the job for the variable element.

In this age of computers, standard data can be stored, retrieved, and accumulated. Several software systems have fundamental motion databases. The software can select, retrieve, and modify the ap- propriate motion or elements to generate a time standard. When properly applied, standard data allow the establishment of accurate time standards prior to actual production quickly and consistently. This is especially useful for estimating the cost of new products or work, preparing quotations and for subcontracting purposes and for establishing standards for indirect labor. In addition, this technique provides management with fair and proven satisfactory standards that help alleviate labor– management conflicts.