Direct materials are items listed in a bill of materials, like raw materials and transportation costs. Indirect materials are consumed but not listed in the bill of materials, like tools, machinery, and equipment. Fixed expenses like depreciation are constant in the short-term, while variable expenses like direct labor fluctuate. However, in the long-term all expenses can be varied as equipment is replaced. Every company has a vision, mission, code of conduct, and core values to guide employees and stakeholders like customers, suppliers, shareholders, and society. A good company focuses on achieving economic, societal, and environmental profits to create sustainable value for all.