Room 9 of 10

Keep the revision and its reason

Our question

What does “ready” mean when an order has partial handoffs?

Back at Harbor Coffee

Sam adds a new fact: a customer sometimes takes the drink first and collects food afterward. Our one-handoff sketch cannot express that history. The earlier three observed orders were handed over complete; this exception arrives later.

Ask Sam and Maria whether “ready” means drink ready, food ready, or the complete order ready. An Order Ready event is like an envelope: knowing that it occurred may not tell us which items were ready. Its contents may matter to the question.

A revision conversation

Scripted engineer–AI illustration

Engineer: Our sketch gives each order one handoff. Sam says drinks and food can be collected separately.

AI: Then an order can have several handoffs. We could record the time and items for each one.

Engineer: That fits the new account. We still need Sam to confirm whether the waiting measure ends at the first item or the completed order.

Try a modeling decision

How should the sketch respond to Sam’s new account?

Choose a view to see what it makes visible.

On the whiteboard

Purpose → What does “ready” mean when an order has partial handoffs?

Read the worked explanation

Before: Order has one Handoff time. After: Order has several Handoffs, each carrying time and items. Preserve the old sketch and cite Sam’s new account. The first-versus-final waiting definition remains a question for the organization.

Room not yet explored. Capstone progress is separate.

Inspect the source

A new fact from Sam

Participant accountsupported

Sometimes a customer asks for the drink first and collects the food afterward. One order can have more than one handoff.

A new exception. The earlier three observed orders were handed over complete.

Name the concept

Event / transaction: An event is an occurrence, such as Order Placed. A transaction records an agreed unit of activity; its boundary and completion need a definition.

Attribute / property: A descriptive fact attached to something, such as an order’s accepted time. It can become a separate thing when identity or history needs to be represented.

Cardinality: How many instances can participate in a relationship: one, several, or none where the rules allow it.