Final answer:
Microsoft has improved the procurement part of its value chain by providing formal reviews of suppliers, clarifying expectations and standards.
Step-by-step explanation:
The correct answer is procurement.
Procurement is the part of the value chain that involves sourcing and acquiring the necessary materials, goods, and services needed to produce a company's products or services. By providing formal reviews of its suppliers, Microsoft has improved its procurement process, clarifying expectations for suppliers and ensuring that they meet the company's standards.
Examples of how Microsoft has improved procurement include implementing supplier evaluation systems, conducting supplier audits, and establishing clear requirements and performance metrics for suppliers.