The Research & Development Department controls the company’s product line. The line currently has five sensor models and can grow to as many as eight.

Your customers are concerned with four product characteristics:

• Size: How much the sensor weighs and the amount of space it takes;
• Performance: How fast the sensor measures and reports physical conditions;
• Reliability: How long the sensor lasts before it fails;
• Age: The amount of time since the sensor was invented or revised.