Writing the Requirements Chapter 10

The Volere Requirements Specification Template Project Drivers The Purpose of the Project The Client, the Customer, and Other Stakeholders Users of the Product Project Constraints Constraints Naming Conventions and Definitions Relevant Facts and Assumptions Functional Requirements The Scope of the Work The Scope of the Product

Nonfunctional Requirements Look and Feel Requirements Usability and Humanity Requirements Performance Requirements Operational and Environmental Requirements Maintainability and Support Requirements Security Requirements Cultural and Political Requirements Legal Requirements Project Issues Open Issues Off-the-Shelf Solutions Risks Costs User Documentation and Training

The Client, the Customer, and Other Stakeholders The client is the person who pays for product development. The customer is the person who buys your product.

Naming Conventions and Definitions Definitions of All Terms Used in the Project

The Shell The functional and nonfunctional requirements should be written more formally using an agreed structure.

Start by identifying the requirement Start by identifying the requirement. Each requirement has three pieces of identification: its number, its type, and the event(s) and/or use case(s) Requirement Number Each requirement must be uniquely identified using a simple sequential number. Requirement Type The type comes from the Volere Requirements Specification Template. The template includes 27 sections, each of which contains a different type of requirement. Event/Use Case Number Give each business event a number for convenient referencing.

Description Rationale The description is the intent of the requirement. It is an English (or whatever natural language you use) statement in the stakeholder's words as to what the stakeholder thinks he needs. Rationale The rationale is the reason behind the requirement's existence. It explains why the requirement is important and how it contributes to the product's purpose. Originator The originator is the person who raised the requirement in the first instance, Fit Criterion A fit criterion is a quantified goal the solution has to meetin other words, it is an acceptance criterion.

Customer Satisfaction and Customer Dissatisfaction The satisfaction ranking is a measure of how happy the client will be if you successfully deliver an implementation of the requirement. The scale ranges from 1 to 5, where 1 means that the client is unconcerned about the outcome and 5 means that the client will be extremely happy if you successfully deliver a product that meets the requirement. The dissatisfaction rating is also on a scale of 1 to 5. This time the rating measures the amount of unhappiness the client will feel if you do not successfully deliver this requirement. A 1 means that the client will be unconcerned if the product appears without this requirement; a 5 means that your client will be extremely angry if you do not successfully deliver this requirement.

Priority The priority of a requirement is the decision on the importance of the requirement's implementation relative to the whole project. Conflicts Conflicts between requirements mean there is some disagreement between them, or one requirement makes another requirement less possible. Supporting Materials material that is important to the requirements

Writing the Specification

Example: Functional Requirements

Example: Nonfunctional Requirements

Summary Writing a good requirements specification is important. A well-written specification pays for itself many times over the construction is more accurate, the maintenance costs are lower, and the finished product accurately reflects what the customer needs and wants.

Quiz Create a Volere Shell for the following FRQ and set it’s priority to High. Description: The product shall record the weather station readings. Fit criterion: The recorded weather station readings shall match the readings sent by the weather station.