Data Type Requirements

Definition

A data type requirement is a data requirement that specifies an aspect of the type of mandatory data about an application, component, or business object.

Objectives

The typical objectives of a data type requirement are to specify the following information about mandatory data:

• Name
• Attributes and components
• Initial Default Values
• Range (i.e., possible values)
• Units of measure
• Volume (e.g., optionality and cardinality)
• Update frequency and type (e.g., periodic, random)
• Relationships:
  • Association
  • Aggregation
  • Generalization, Specialization, and/or Subtyping
  • Invariant relationships among the data

Examples

The following are typical examples of data type requirements:

• “The application shall successfully handle (i.e., CRUD) the following information about each customer:
  • Customer Name.
  • Customer Unique Identifier.
  • Customer Contact Information:
    • Mailing Address.
    • Email Address.
    • Telephone Number.
  • Customer Accounts.
  • Customer Credit Information:
    • Credit Card Information:
      • Credit Card Type.
      • Credit Card Number.
      • Credit Card Expiration Date.
      • Credit Card Name.”
• “The application shall successfully handle customer names up to 80 characters in length.

Guidelines

The following guidelines have been found to be useful when producing data type requirements:

• Data type requirements can be specified textually in a data dictionary or graphically using an appropriate diagram.