While examining the logical architecture of hms_sys in Chapter 7, Setting up Projects and Processes, a handful of common business object types surfaced across the entire scope of the system:

The objects, as displayed in the preceding diagram, are explained as follows:

• An Artisan object represents a single Artisan—an end user who creates product items to be sold, and who makes those products available to the HMS Central Office through the system. Artisans are collected in the Central Office's data structure, and can be managed to a certain extent by Central Office staff, but the majority of their actual data needs to be owned and managed by the individual artisans themselves; that way, they have as much control over their information as possible, and Central Office staff aren't put in the position of managing data changes for artisans if, for example, they change their address, or want to add or change a company name.
• A Product is a representation of a physical object, something that an Artisan has created that is for sale.
• An Order is the result of a customer placing an order for a Product through the HMS web store.

These three object types also infer two others that were not called out earlier:

• A Customer, representing an actual customer that placed an Order, and that can be attached to one or more orders
• An Address, representing a physical location that something could be shipped to or from, which can also be attached to one or more orders, may be a property of a Customer, and almost certainly will be a property of an Artisan

This chapter will cover the implementation of those objects as a common class library that can be leveraged by the application and service projects' code, including the design, implementation, automated testing, and build process that turns it into a deployable package.

This chapter covers the following:

• Iteration goals
• Assembly of stories and tasks
• A quick review of classes
• Implementing the basic business objects in hms_sys
• Testing the business objects
• Distribution and installation considerations
• Quality assurance and acceptance
• Operation/use, maintenance, and decommissioning considerations