Fundamentals of Standard Data Systems for Work Measurement

What are Standard Data Systems (SDS)?

A Standard Data System (SDS) is a database of normal time values organized by work elements. It is used to establish time standards for tasks composed of those work elements. A key feature is that time standards can be established before the job is actually performed.

When is an SDS Suitable?

A Standard Data System is particularly suitable in situations involving:

• A high degree of similarity between tasks.
• Batch production environments.
• A large number of standards that need to be set.
• The need to set standards before production begins.

Using a Standard Data System

The process for using an SDS typically involves the following steps:

1. Analyze the new tasks and divide them into their constituent work elements.
2. Access the database to determine the normal times for these work elements.
3. Sum the element normal times to obtain the total task normal times for both setup and the production cycle.
4. Compute the standard times for setup and the production cycle by adding the appropriate allowances.

The SDS Database

The core of an SDS is its database, which is a catalog of normal times. It is organized to allow an analyst to access values corresponding to work elements performed under various conditions, known as work variables.

Work variables are defined as factors that affect the normal time of a work element.

Developing a Standard Data System

The development process involves several key steps:

1. Define the objectives of the system.
2. Define the coverage of the system (i.e., which tasks it will apply to).
3. Obtain work element normal time data.
4. Classify the work elements.
5. Analyze the data to determine element normal times.
6. Develop the database structure to predict normal times.
7. Prepare comprehensive documentation.

Classification of Work Elements

Work elements can be classified in several ways:

• Setup vs. Production
• Constant vs. Variable Elements
• Operator-Paced vs. Machine Elements
• Regular vs. Irregular Elements
• Internal vs. External Elements

Work Cycle Standard Data

This is a type of Standard Data System that uses normal times for the entire task rather than dividing the task into work elements and determining individual element normal times. This approach is useful when:

• The work elements of a task are highly variable.
• The elements are difficult to separate or identify.
• The task consists of a very large number of elements.
• The elements are very similar to each other.

Calculating Machine Times

Machining is a family of processes in which excess material is removed from a starting workpiece by a sharp cutting tool so the remaining part has the desired geometry. Common operations include turning, drilling, and milling.

Machine times can be calculated with great accuracy given the machine settings (e.g., feeds and speeds) and the part's dimensions.

Advantages of Standard Data Systems