This chapter will help you to understand how to prepare Functional Design Documents (FDDs) and Technical Design Documents (TDDs). We will cover what FDDs are and how they are used. We will also cover the information that is commonly included in an FDD. This chapter will help you to know more about the features of a good FDD.

Next, you will learn about TDDs and the information commonly included in a TDD. You will also learn about infrastructure diagrams for a mid-sized Dynamics 365 CE deployment. Later, you will understand the Dynamics 365 CE application architecture and its extension points. 

The main topics that we are going to discuss in this chapter are as follows: 

• Understanding functional and technical design
• Preparing an FDD
• Preparing a TDD