STEP 4. PRELIMINARY DESIGN DOCUMENT (PDD)

Table of Contents

Project Title

Management Summary

  1. Introduction
    1. Project Background
    2. Plan Objectives
    3. References
  2. System Overview
    1. Business Processes
    2. System Users
    3. Dependencies And Limitations
  3. Functional Design
    1. Software/Hardware Design
    2. Data Design And Control
    3. Computer/User Interface Design
    4. System Interface Design
    5. Security Design
  4. Requirements Cross Reference
  5. Approval/Concurrence
  6. Glossary

Appendices

 

PRELIMINARY DESIGN DOCUMENT (PDD) INSTRUCTIONS

Project Title

Enter the name of the project.

Management Summary

The preliminary design document is developed in conjunction with the requirement analysis process to communicate the hardware and software components necessary to satisfy user requirements.

  1. Introduction
    1. Project Background

             Describe the software project for which this design is developed. Identify the system owner.
    2. Plan Objectives

             Briefly describe the objectives of the PDD; e.g., describe the software design in the user’s terminology, provide a guide for a more technical design document, or ensure that customers and software developers have a common understanding of the software design.
    3. References

    Identify sources of information used to develop this document. Include documents that define and trace system requirements; e.g., Feasibility Assessment or Requirements.

  2. System Overview
    1. Business Process

             Reference the business processes modeled by the system. List any organizational functions served by the system; e.g., payroll, human resources, production, etc.
    2. System User

             Identify the potential system users. Specify the levels of expertise needed by the various user types and indicate how each user type will interact with the system; e.g., data entry clerk and the systems coordinator, etc.
    3. Dependencies and Limitations

List dependencies or limitations that may affect the design of the software. Examples include budget and schedule constraints, staffing issues, availability of components, etc. Describe how each factor will affect the functional design.
  1. Functional Design

3.1 Software/Hardware Design

Decompose the system software/hardware into design entities or objects that interact with and transform data to perform the required system objectives. Assign a unique name to each design entity and group entities by type; e.g., class, object, and procedure. Describe how each design entity satisfies system requirements. In user terminology, specify the inputs, outputs, and transformation rules for each design entity. Depict how design entities depend on one another.

3.2 Data Design and Control

Identify specific data elements and logical data groupings stored and processed by the design entities in 3.1 above. Outline data dependencies, relationships and integrity rules in a data dictionary. Specify the format and attributes of all data elements or data groupings.

3.3 Computer/User Interface Design

Describe the user interface and the software operating environment including the menu hierarchy, data entry screens, display screens, online help and system messages. Specify where in this environment the necessary inputs are made and list the methods of data outputs; e.g., printer, screen, and file. Note any design standards applied. If project human-machine interface design standards have been developed, discuss them in this section.

3.4 System Interface Design

Specify how the software product will interface with other systems. For each interface, describe the inputs and outputs for the interacting systems. Explain how data is formatted for transmission and validated upon arrival. Note the frequency of data exchange.

3.5 Security Design

List any access restrictions for the various types of system users. Describe any access code systems used in the software. Identify any safeguards protecting the system and its data. Specify communications security requirements.
  1. Requirements Cross Reference
    2.

    For each numbered system requirement, identify the section(s) of this document that specify how the PDD will meet the requirement.

  2. Approval/Concurrence

    3. Include an appropriate SC concurrence/approval section.
  3. Glossary

Provide a glossary of all technical terminology used with the document.

Appendices

Use appendices to document any specific alternative vendor information.