Ada 95 Transition Support
4.1 Executive Summary
The JSF-SFD Ada 95 project will reuse the existing F-22 Sensor Fusion Software, written in Ada 83, to investigate Ada 95 tool sets and the suitability of several aspects of the Ada 95 language for embedded, real-time environments. The project is being conducted by Boeing Defense and Space Group with Hughes as a subcontractor.
The project will consist of re-engineering an existing portion of the F-22 Sensor Fusion Software to an Ada 95 implementation and rehosting the system to new target hardware. The newly re-engineered software will be included in the Sensor Fusion Software on the Joint Strike Fighter.
The entire project including training, analysis, design, implementation and testing, began in early August 1996 with a kickoff meeting at Seattle, Washington, the site of Boeing Defense and Space group. As of this Summer 1996, the only phase of the project to commence is the training phase which began on September 9, 1996. Since the project is in such an early phase, the lessons learned are quite limited.
The following summarize the major lessons learned while supporting this project:
- As of Summer 1996, commercial Ada 95 classes for embedded, real-time environments are scarce.
- As of Summer 1996, currently available commercial Ada 95 classes are lacking in depth and sophistication.
4.2 Project Introduction and Overview
The JSF-SFD Ada 95 project will reuse the existing F-22 Sensor Fusion Software, written in Ada 83, to investigate Ada 95 tool sets and several aspects of the Ada 95 language. The project is being conducted by Boeing Defense and Space Group with Hughes as a subcontractor.
The project will consist of re-engineering an existing portion of the F-22 Sensor Fusion Software to an Ada 95 implementation and rehosting the system to new hardware. The portion of the F-22 software selected for upgrading includes the following modules from the Integrated Core Processor: Sensor Track Fusion, Mission Management, Sensor Tasking, and Sensor Control. Taken in concert, these modules form a continuous feedback loop responsible for providing the pilot with an integrated view of the numerous sensors on the Joint Strike Fighter.
4.3 Project Goals
Questions to be answered as part of the JSF-SFD effort are:
- How well do Ada 95 tools compile Ada 83 code?
- Do Ada 95 enhancements allow Ada 83 code to be improved with regard to:
- Are Ada 95 toolsets mature enough to handle a large project?
- Can Ada 95 toolsets be readily applied to JSF projects?
- Is Ada 95 suitable for an embedded, real-time environment?
- What are the benefits of Ada 95 over Ada 83 in an embedded, real-time environment?
This project will be conducted by the Space and Defense Group of Boeing with the support of The Ada Joint Program Office (AJPO). Hughes is a subcontractor to Boeing and is responsible for the port of the AOS operating system from Ada 83 to Ada 95.
Ada 95 training was provided on September 9-12, 1996 at the Boeing Defense and Space facility in Kent, Washington. Training was provided, as part of the AJPO Transition Partnership Efforts, by Dr. Ben Brosgol of Thomson. The training lasted a total of four days. The instructor and students were both pleased with the training experience and the resulting competence gained.
- Ada 95 training must match the technical requirements of the project.
The focus of Ada 95 training courses varies greatly. It is essential to choose an appropriate one. In order to ensure that the choice of class material was appropriate for the needs of the Joint Strike Fighter project, the AJPO-sponsored Ada mentor attended the Ada 95 course and assisted with presentation and prioritization of instructional materials.
- Ada 95 training must meet the educational needs of the students.
Instructors vary widely in their teaching approach and educational skills. In this case, the strong technical skills of the Boeing employees required an instructor with a great depth of knowledge. Therefore, Dr. Brosgol was the best choice among the available training options based on his participation in the development of the Ada 95 standard.
- Embbedded, real-time training in Ada 95 is not readily available.
As of Summer 1996, the current marketplace does not include anything but the most basic Ada 95 classes. Of the major players, Adaworks, Pat Rogers of Software Arts and Sciences, Thomson, etc., only Pat Rogers offers any embedded, real-time training in Ada 95. Many of the companies are willing to put together a course given a firm contract but off-the-shelf, ready-to-go courses are scarce to non-existent.
- The maturity of Ada 95 classes is poor.
Most, if not all, of the currently available Ada 95 classes are at the basic level of describing the syntax and, sometimes, the semantics of the language; any further instruction is sparse. Few courses deal with designing solutions using Ada 95 and even discussions of trade-offs among language features is rare.
The Joint Strike Fighter Sensor Fusion project has now taken the first step toward a transition to Ada 95. Further training/mentoring will be required to provide the development team with an initially comprehensive understanding of the language. Given the state of the market, it is assumed this transfer of knowledge will have to be done on an as-needed basis by the AJPO-sponsored mentors.