Instructions tell people how to perform a process. Because processes are so common in engineering, engineers often write instructions. For example, you may have to write specifications to technicians on how to machine a drive shaft, or you may have to write a software manual for computer users on how to run a contour-plotting program. You may even have to instruct the public on the safety precautions for using a snow blower that your company manufacturers. Each of these three examples points to the importance of well-written instructions in engineering. If the specifications for the drive shaft are unclear, your company may have to resubmit the job (at your company's expense). If the software manual is disorganized, users of the program may waste valuable time searching for a command. If the safety precautions for your company's snow blower are ambiguous, someone could be injured. Money, time, and health often depend of the quality of the writing in instructions.
In engineering, the formats of instructions can vary from single-phrase cautions on clothing to thick handbooks on procedures in nuclear submarines. Instructions have four unusual aspects of style. First, instructions often include numbered steps. Using numbered steps with white space between each step allows readers to perform a step of the process and then quickly find their place in the instructions. Also, instructions include the use of the imperative mood, in which the subject is an understood you (for example, "Learn the basic procedures of first aid"). Note that you do not use the imperative mood in every sentence; however, you often use it for important steps. In the language for instructions, you also use cautions to warn readers of difficult or dangerous steps. Finally, with instructions, you use more illustrations or examples than with other types of documents. The following example is a set of instructions for what to do in case of a snakebite. For more discussion about the style of instructions, see Chapter 14 of The Craft of Scientific Writing.
In putting together a set of instructions, you might have to write or present as part of a group. Collaboration presents challenges to group members: connecting the different ideas of the group members, making the language read as if it were from "one voice," and choosing a consistent format for the final product. Although collaboration on a document or presentation presents challenges to the group members, it also has advantages. One advantage is that working in a group broadens the range of ideas that the document or presentation can incorporate. Another advantage is that collaborative work allows the group to draw from the various writing and editing strengths of the members. In a successful group effort, you find a strategy that accents the advantages and mitigates the disadvantages.