“How you do and what you do is going to decide how long you will take to do it”. Time is a by-product of method being followed. SAM (Standard Allowed Minute) or SMV (Standard Minute Value) of an operation is a common way of expressing work content of an operation in terms of minute value. But there is a great deal of conceptual understanding that goes behind calculating the same. The normal time for an operation is defined as the time that a qualified operator would take to perform the job if he or she works at a normal tempo.
Time Study is the only way to measure work content of any operation
Time study is one of the two ways of measuring work content of any operation. Use of PMTS (Predetermined Motion Time Systems) is the second method by which work content of any operation can be estimated. For measuring work content by time study, operation has to be in progress. The work study engineers actually observe the operation, measure time using stopwatch, add allowances and arrive at standard minute value. Through PMTS, any PMTS practitioner can estimate the work content of an operation in advance.
Rating is a very subjective process
Operator performance or operator rating is in a way indication of how normal, skilled, effective, correct and consistent they are. Operator performance (also called operator rating) is a key ingredient to arrive at Standard Allowed Minute. Once the time is recorded by stopwatch by work study engineers, one has to assess the rating of operator. The rating system requires an analyst to evaluate the operator’s skill, effort, the environmental conditions of the workplace, and the consistency between elemental time values. It also attempts to evaluate the speed of an operator’s motions, dexterity and the effectiveness of motions employed to perform the task. There are different rating systems being followed; however, all resort to qualitative measurement parameters, a few of which are mentioned above. This is basically subjective assessment of many objective parameters.
Higher the rating, higher will be the operator’s skills
One should not confuse between multi-skilling and performance. In my experience in Indian factories, operators are generally graded as A, B or C based on how many different types of operations they can perform (often having a direct correlation with their experience). These grades are often misused as their performance indicators, which is incorrect. Performance or rating indicates how an operator can perform an operation (a skill), and has no relation with how many different operations he/she can perform. After all, one can be either master of few or jack of many.
Personal and fatigue allowances are constant for all organizations
Personal allowances are basically to take care of personal needs of individuals like toilets, drinking water, etc. Although the amount of personal time required will vary with individual more than with the kind of work, it is a fact that employees need more personal time when the work is heavy and done under unfavourable conditions. It is said that for light work (e.g. garment sewing jobs), where the operator works 8 hours per day without any organized rest periods, 2% to 5% time on average will be allowed for personal needs. The word “unfavourable conditions” is very important, it is observed that on a hot and humid day without proper air cooling system in sewing floor and a drinking water facility at a distant, may result in 13% personal allowance! At present there is no fully satisfactory way of measuring fatigue. Time needed for rest varies with individuals, with the length of interval in the cycle during which a person is working under the load and atmospheric conditions, besides many other factors. Personal and fatigue allowances may be estimated by conducting a work sampling study (or ratio delay study).
Time study is a manual complicated process
Earlier time study (more so for method study) used to be done by trained and qualified industrial engineers. A time study board, decimal stopwatch, time study sheet and pencil were used. The industrial engineers are required to have good hand eye coordination for simultaneous observation and writing ability. Now videography and software tools are available which has de-skilled the process and any supervisor can conduct video time study with minimal training.
All PMTS are proprietary data, hence costly
PMTS is a database of different operation sewing times for method analysis and setting up of time standards for needle trade environment such as cutting, sewing, pressing, examination and packing. All PMTS is based on MTM (Methods Time Measurement) database, which is freely available. Proprietary PMTS database like GSD, Pro-SMV, Seweasy, etc. are carefully selected improvised data code customized for sewn products industry. However there is one PMTS called SPD (Sewing Performance Data), which is available in books. GSD consists of 25 codes at the general level, supplemented by Get/Put data and selected MTM codes for complete coverage. The basic motion sequences used are Get/Put data from MTM core data. There is also a sewing formula to calculate time spent in sewing.
PMTS can decide the correct method for an operation
Once you define the method, PMTS can tell you the time required for that method. Remember PMTS can’t decide the right method for an operation. PMTS is merely a database specific to an industry, all perceived hand motions possible for performing sewing operations will be found in the database. The practioner should be able to either see an operation being performed or visualize how the hand movement is to be performed and match the correct code from the database.
All PMTS are designed for sewing operation
Although majority of commercially available PMTS systems are customized for sewing operations, similar concept can be used for cutting and finishing operations also. GSD Limited has a module of PMTS solution called GCD (General Cutting Data) meant for spreading, cutting, bundling, ticketing and other activities of cutting room.
Popular PMTS systems like GSD, pro-SMV are actually software
The heart of any PMTS system is the practitioner; software is only a database of customized code timings. It is the practitioner who visualizes the element wise hand movement of any operation and decides on which code would aptly fit. As you keep deciding on codes for an operation the timings are automatically retrieved from database and added. The software also stores common macros for repetitive and commonly used operations for quicker calculations. The software acts as library of operation timings and over the years act as handy reference database for similar operations.
PMTS databases can’t work for different fabric types, hence impractical
PMTS database are not made material-specific. Due to variation of material type, the operator may need to change method. PMTS database is method-specific, so it will work for any material. The practitioner has to visualize the difference in hand motions that would be required for different types of fabrics. For example picking up a limpy piece of fabric and aligning below presser foot may require many additional get/put motions and thus will require additional time.