TIME STANDARDS:ESTABLISHING TIME STANDARDS

2. ESTABLISHING TIME STANDARDS

There are two basic strategies: nonengineered (subjective) standards (‘‘did take’’ times) and engi- neered (objective) standards (‘‘should take’’ times). The techniques to use depend upon the cost of obtaining the information and the benefits of using the information.

2.1. Nonengineered (Type 2) Estimates

‘‘Quick and dirty’’ information can be obtained at low cost. But using ‘‘dirty’’ information increases the risk of errors in decisions. Since nonengineered standards are not preceded by methods or quality analysis, they are ‘‘did take’’ times, not ‘‘should take’’ times.

There are four approaches: historical records, ask expert, time logs, and work (occurrence) sam- pling.

2.1.1. Historical Records

Standards from historical records tend to be very ‘‘dirty’’ (although cheap). For example, in the warehouse, how many cases can be picked per hour? From shipping records, determine the number of cases shipped in January, February, and March. From personnel, determine the number of em- ployees in shipping in each month. Divide total cases / total hours to get cases / hr. Ignore changes in product output, product mix, absenteeism, delays, and so on.

2.1.2. Ask Expert

Here you ask a knowledgeable expert how long a job will take. For example, ask the maintenance supervisor how long it will take to paint a room. Ask the sales supervisor how many customers can be contacted per week. A serious problem is that the expert may have an interest in the answer. For example, a ‘‘hungry’’ maintenance supervisor wants work for his group and so quotes a shorter painting time; a sales supervisor may be able to hire more staff (and thus increase her prestige and power) by giving a low estimate of customers / sales representative.

2.1.3. Time Logs

It may be that a job is ‘‘cost plus’’ and so the only problem is how many hours to charge to a customer. For example, an engineer might write down, for Monday, 4.0 hr for project A, 2.5 hr for B, and 3.5 hr for C. Obviously there are many potential errors here (especially if work is done on project D, for which there no longer is any budget).

2.1.4. Work (Occurrence) Sampling

This technique is described in more detail in Chapter 54. It is especially useful when a variety of jobs are done intermittently (e.g., as in maintenance or office work). Assume that during a three- week period a maintainer spends 30% of the time doing carpentry, 40% painting, and 30% miscel- laneous; this means 120 hr X 0.4 = 48 hr for painting. During the three-week period, 10,000 ft2 of wall were painted or 10,000 / 48 = 208 ft2 / hr. Note that the work method used, work rate, delays, production schedule, and so on are not questioned.

2.2. Engineering (Type 1) Estimates

Engineered estimates of time must be preceded by a methods and quality analysis; the result is a ‘‘should take’’ time, not a ‘‘did take’’ time. MIL-STD-1567A requires for all individual type 1 stan- dards (assuming the basic standards system is in place):

1. Documentation that the method was analyzed before time was determined

2. A record of the method or standard practice followed when the time standard was developed

3. A record of rating (if time study was used)

4. A record of the observed times (if time study) or predetermined time values were used

5. A record of the computations of standard time, including allowances

You would not expect a time standard established in 1960 to be valid today; things are different now, we think. But what differs? Thus, step 2 (record of method followed) is essential information for maintaining standards.

There are two basic ways of determining time / job: stopwatch time study and standard data.

2.2.1. Stopwatch Time Study

Stopwatch time study, which is described in detail in Chapter 54, requires an operator to do the operation; thus it cannot be done ahead of production. In general, it requires the operator to do the operation over and over rather than doing different tasks intermittently (such as might be done in office or maintenance work). Before the timing is done, the method must be analyzed.

In repetitive work, where detailed methods analysis is desired, a videotape of the task can be made; the analyst can study the tape instead of a live operator.

Because of learning, do not do time studies on operators who are early on the learning curve. If the study must be done early, label it temporary and restudy it in, say 30 days.

2.2.2. Standard Data

Standard data can be at the micro level or the macro level (see Chapter 54). In this approach, the analyst visualizes what the job entails (a danger is that the analyst may not think of some of the steps [elements] needed to complete the job). After determining the method, the analyst uses a table or formula to determine the amount of time for each element. The database elements are expressed in normal time (i.e., rating is included), so no additional rating is required. Then normal time is increased with allowances to obtain standard time.

Compared with time study, the standard data method has three advantages: (1) cost of determining a standard is low (assuming you have a database with standard times); (2) consistency is high because everyone using the database should get the same times; and (3) ahead-of-production standards are helpful in many planning activities. But among these three roses are two thorns: (1) you may not have the money to build the database (the databases are built from stopwatch studies and predeter-

mined times); and (2) the analyst must imagine the work method; even experienced analysts may overlook some details or low-frequency elements.