Task: Identify Features
It Involves to determine the features of the products, considering the user stories, the SPL vision and the stakeholders' knowledge.
Disciplines: Product Scoping
Purpose
Identify the features of the products.
Relationships
RolesPrimary Performer: Additional Performers:
InputsMandatory:
    		Optional:
    • None
    Outputs
      Main Description

      The task identify features is performed across of a workshop which presents four steps: evaluate stories, identify features related with stories, describe features and analyze priority. In this workshop, the user stories are evaluated to determine which features can be extracted of them.

      The features have equivalent priority to the stories of the which were extracted. Each story is also evaluated for identify if are feasible and completes. With this, the workshop participants can identify features which were not covered by the user stories, but which are important for the products and determine the features which are not feasible, factor which can cause the reprioritization of the features. in the repriorization should be considered the objectives and constraints identified in the task of pre-scoping meeting.

      Each feature has one name, description and priority associated to them. The priority can be: I. High, the feature is essential for the user and the product line cannot derive product without this feature; II. Medium, the feature is important for the user, the inclusion of this feature will get benefits for the user; III. Low, the presence of this feature will get additional value for the user, but it can be clearly omitted of the product line.

      The existence and priority of the features are discussed in the workshop by all integrants and in cases of discussion about critical features, timeboxes can be determined to limit the time and to provide agility at the workshop.

      Steps
      Evaluate Stories

      In this step, each story is analyzed separately. In this analysis two points are considered: 1. if the story is feasible, factor that influences in the priority of the story and 2. if it is complete, factor which influences in the discovered of new important features related with the stories, but which were not described by the customers.

      Identify Features Related with the Stories

      The features identification is made base on the stories. The features should have, initially, equal priority to the stories of which were extracted.

      In this approach functional and non-functional features are considered. The functional features are related with aspects as “what” the system has which do. The non-functional features are associated with quality attributes, which the products should address. These attributes will serve as architectural drivers of the product line and presents impact in the product line architecture. Therefore, the identification of non-functional features is of extreme relevance for the architecture of the product line. Some types of quality attributes are descript below: 1. usability, it is related with the facility which the users have of using the system; 2. performance, it is related with the time of response of the system; 3. security, it is related with the ability of the system to prevent or to resist unauthorized access; 4. portability, it is related with the eased of porting the software for other machines and operational systems; 5. availability, it is related with the amount of faults of the system; and 6. maintainability, it is related with the eased for maintaining the system.

      Describe Features

      After the identification, each feature is descript. The features should be descript briefly. 

      Analyze Priority

      The priority analysis is the final step of the task identify features. In it, the features are reprioritized case necessary. This is made according to the stakeholder's knowledge, considering the business value determinated by the customers.