Technical Specifications Document (TSD) – Definition

A technical specification document defines the requirements for a project, product, or system.
A specification is information on technical design, development, and procedures related to the requirements it outlines. This document provides information to developers and other stakeholders on business requirements, internal standards, and best practices.

The technical specifications document is usually written after the fact, to document the finished product and are not part of the design documents. This document describes the minute detail of either all or specific parts of a solution such as:

• The signature of an interface, including all data types/structures required (input data types, output data types, exceptions).
• Detailed class models including all methods, attributes, dependencies, and associations.
• The specific algorithms that a component employs and how they work
• Physical data models including attributes and types of each entity/data type.

During a project, this document will usually be built upon as the project is progressing to ensure the end result reflects the work that has been completed. TSD documents are usually written by:

• Technical Project Managers
• Solutions Architects
• Senior Technical Leads
• Senior Engineers