Final answer:
The most suitable software process model for expedited development of a word processing software package is Agile.
Step-by-step explanation:
The customer wants to develop a word processing software package in an expedited manner. In this case, the most suitable software process model to follow would be the Agile model. The Agile model emphasizes iterative development, frequent communication, and flexibility. It allows for quicker delivery of functional software and accommodates changes and customer feedback throughout the development process.