Let’s start with an activity that is performed by a single person. To simplify things further, let’s assume that the employee works full-time on the single activity. Imagine, for example, that the activity involves the entry of expense report information into a ledger. We hope no one does something like this without using a computer system today, but let’s imagine that this activity is an entirely manual operation. In other words, there is a job description, describing the work of an Expense Report Entry Clerk, and there is a one-to-one relationship between the job description and the work done in the Enter Expense Reports activity.
If we were going to analyze this activity, we would begin by obtaining copies of expense reports and a correctly updated expense report ledger. Then we’d sit down with a skilled Expense Report Entry Clerk and watch her do the job. We’d take notes to describe the steps and actions taken by the clerk as she received the reports and then created the updated ledger. We assume the clerks would do things like stamp the incoming expense report with a date, and then examine it to see that it was complete. If it was complete, the clerk would probably proceed to copy information from various locations on the expense report to other locations on the ledger. In some cases numbers would be added and sums would be entered. After the entry was complete, the original report would probably be filed, and the ledger numbers added or subtracted to reflect a change in various balances. If the original report was incomplete, we assume the clerk would follow some alternative path. For example, the report might be turned to the sender with a note pointing out that additional information was required.
In other words, the activity would be composed of a number of steps or tasks. The steps would be triggered by the receipt of an expense report and terminate when the report was filed and the ledger was completely updated. Obviously we could create a diagram showing each step and use arrows to show how the clerk moved from one step to the next, and where decisions and branches occurred. In this case, however, the analyst decided he or she didn’t need a model and that a list of steps would suffice.