While an Epic typically defines an initiative of a large scale that spans a long period of time, Features are defined in a manner that can be easily digested by the business, prioritized at the Program level, and implemented within a single Program Increment (PI). The Scaled Agile Framework® defines a PI as:
A Program Increment (PI) is a timebox in which Agile Release Trains deliver incremental value in the form of working, tested software and systems. PIs are typically eight to twelve weeks long, and the most common pattern for a PI is four development iterations, followed by one Innovation and Planning iteration.1
Feature decomposition involves multiple stakeholders from across a program organization. A Product Manager typically works with Product Owners to define business Features that describe functionality that provides direct value to customers. However, Features may also be enablers, necessary to explore and establish the architectural foundation required to meet the business needs. Architects or Engineers typically assist by deconstructing enablers at the Epic level and by defining the enablers at the program level that are necessary to support the business Features of an Epic.
Features composing an Epic are described using a matrix of Features and benefits. The Feature can be described by a short phrase, while the benefit or benefits of each feature should succinctly describe how the Feature benefits the business. For example, a Feature to export calculated data might benefit the business by adding the ability to share or repurpose data with other groups. Each Feature must also have acceptance criteria. In the case of Features, the acceptance criteria are defined to help the business establish the expected behavior or outcomes of a Feature. From these, the business should be able to determine if the implemented Feature delivers the expected benefits.
During decomposition, Epics can be split into Features by a variety of factors, including business priority, workflow, effort, complexity, data/service needs, and more.