Connecting Objects: Placing Objects Inside Others

One way to connect objects is to place one object inside another. The contained object is called a Child Object, and the containing object is its parent.

Examples include:

• order lines inside an order
• tasks inside a project
• inspection records inside an asset
• contacts inside a customer

Use ownership as the guide​

A Child Object belongs to its parent and normally makes sense only in that context. An order line, for example, is part of one particular order rather than an independent business object reused elsewhere.

A useful question is: Could this object reasonably exist without its parent? If the answer is no, placing it inside the parent is usually the right model.