​In a sequence diagram, vertical arrows represent messages from one object to another.

​The _____ is the most pessimistic outcome of a task.

A _____ represents the work that one person can complete in one day.​

​In a use case diagram, the user becomes a(n) _____, with a specific role that describes how he or she interacts with a system.

​In the rapid application development (RAD) model in the accompanying figure, the _____ phase focuses on program and application development tasks similar to the SDLC.

​Identify is a typical example of a system requirement for the performance category.

_____ refers to the practical resources needed to develop, purchase, install, or operate a system.​

​_____ means that a proposed system will be used effectively after it has been developed.

​Projects where management has no choice in implementing them are called _____ projects.

In a systems development life cycle (SDLC) model, the purpose of the _____ is to create a physical model that will satisfy all documented requirements for the system.​