Developmental/Unit Test and Integration

During the Developmental/Unit Test and Integration phase, engineering components are physically integrated into successively larger aggregates of hardware and software. Tests are developed and conducted to assure that the functions defined by the preliminary and detailed designs are being accomplished, including performance requirements, error detection and recovery, and degraded operations.

Inputs

1. 1. End item requirements and design documentation.
2. 2. Interface Control Documents (ICDs).
3. 3. Engineering hardware and software components that were the result of the Development and Fabrication phase.

Process

The engineering organizations responsible for the hardware and software end items begin testing them to make sure they meet their lowest level objectives, in accordance with the processes defined in their respective development plans. Systems engineering (SE) supports this process by helping to evaluate the scope and appropriateness of proposed changes and corrections and also by helping to assess the impacts of these changes and corrections on system level requirements, designs, and planned test activities. SE also helps assess if there are any impacts to, or introduction of, risks that affect the system level or higher.

Hardware units that pass the lowest level verification processes are then physically integrated into successively higher levels so that verifications allocated to those higher levels may begin.

Similarly, code that passes initial unit testing is integrated into successively higher levels and subjected to verification, up to the level of a complete Computer Software Configuration Item (CSCI).

Anomalies are documented, corrected, and the units are reverified until the respective verification goals have been met. SE monitors this process as described.

Outputs

1. 1. Informally verified hardware and software.
2. 2. Corrections as needed to requirements, design, and interface documents.
3. 3. Ongoing evaluations of Technical Performance Measurements (TPMs).

Milestone Reviews

Generally, there are no formal milestone reviews during this period. However, for safety critical systems the integration and verification activities may be performed by a team independent of the initial developers.