A Continuing Series from Mr. Procedure

The batch-oriented work instruction, described in Part 3, intends that the process performer use their task learning to complete a recurring batch of product. A set of instructions to mix ingredients is supplemented by instructions on how to operate the mixer. Since the mixer is operated the same way regardless of the ingredients added, the operator need only learn mixer operation once and apply that learning to any subsequent mix. Each work instruction is freed from having a tutorial on the mixer.

The second type of mix instructions to consider is the assembly-oriented instruction. This type of instruction describes how to build an individual assembly or to integrate assemblies together.

The pre-requisite information for an assembly-oriented work instruction is most frequently the Bill of Materials (BOM) that describes the pieces that go into the assembly and the drawing that illustrates the assembly.

In theory, the BOM and drawing should be sufficient to complete the assembly. I have been told that more than one time by people: why write a work instruction for an assembly when they (the operators) have the drawing?

The answer is that the drawing shows the parts coming together to make a whole, but does not provide the order of events to assemble the item. A work instruction for an assembly provides the order, allowing the assembler to more efficiently build the item without having to assemble by trial-and-error.

The assembly-oriented work instructions will have its own pre-requisites, which will vary by the type and complexity of the assembly being built. We will discuss specific elements of a work instruction for assemblies in a future post, but there are two basic pre-requisites for any assembly:

• The tools and equipment used to complete the assembly
• Any specific skills required to perform the assembly work

Skills can include how to use certain tools (such as precision measuring instruments and torque drivers).

By identifying the required skills to complete an assembly, the organization can assign workers to assembly tasks based on their skill sets. They can also train workers in those skills (similar to task training) to ensure adequate capability in the assembly area.

An example skill—one I dealt with extensively in recent writing jobs—is electrical wiring. If an assembly requires several or many wires to be installed, the instructions have to deal with the wire itself (the color, length and gauge) and the manner of connection (pins, direct placement, soldering, etc.). All of the elements of wiring can be described in simple, linear format if the assembler understands the basics of wiring. Without the external capability development, work instructions would have to be unreasonably lengthy to compensate, and more capable workers would be bogged down in elementary discussions of skills they no longer need.

Why This Matters

The importance of identifying (and establishing) required capability for assembly instructions is identical to the pre-requisite training for batch-operation instructions. A straightforward description of steps is all my work instructions will need for success. Additionally, having pre-identified skills allows the organization to seek out those skills when hiring workers.  

Next, we will discuss work instructions for testing.