Lopez Plastics Company makes just two product lines, plastic casings for pens and plastic casings for cell phones. Pen casings have a simple design and a simple production process. The company produces them in high volumes, using 90% of its direct-labor time. Pen casings rarely require special customer support or engineering work. This means that indirect production-support costs, such as design engineering of the pen casings, will be small. Cell phone casings, in contrast, have a more complex design, and the company produces them in small volumes, accounting for only 10% of its direct labor time. Customers who buy cell phone casings have specific design requirements that cause much production engineering work. Most of the engineering work performed at Lopez Plastics supports the production of cell phones