12.53 Pareto charts.
You manage the customer service operation for a maker of electronic equipment sold to business customers. Traditionally, the most common complaint is that equipment does not operate properly when installed, but attention to manufacturing and installation quality will reduce these complaints. You hire an outside firm to conduct a sample survey of your customers. Here are the percent of customers with each of several kinds of complaints:
| Category | Percent |
| Accuracy of invoices | 25 |
| Clarity of operating manual | 8 |
| Complete invoice | 24 |
| Complete shipment | 16 |
| Correct equipment shipped | 15 |
| Ease of obtaining invoice adjustments/credits | 33 |
| Equipment operates when installed | 6 |
| Meeting promised delivery date | 11 |
| Sales rep returns calls | 4 |
| Technical competence of sales rep | 12 |
12.53
(a) The customers could make 0 or many complaints, not just 1. (b) The three biggest complaints are problems with invoices, so that should be the focus.