AdaIC News Winter 1996

Why Ada?

Some of you have asked for a quick, handy way to sum up some of the important DoD Ada documents and their rationale.

Well, here's a 3" x 5" description thereof -- suitable for cutting out and having handy for the next time someone asks, "Why Ada?"

Why is Ada appropriate?
Support for large, complex systems
Interoperability and maintainability
Software Engineering
Modifiable, reliable, portable, easily integrated, etc.

DoD core competency, lower lifecycle costs
International standard (ANSI, ISO, FIPS)
Only internationally-standardized object-oriented language
Only language with required validation
Promotes reuse, portability
Not locked into proprietary vendor
Most companies settle on a standard, why not DoD?

60-80% of software costs are in maintenance
Ada best in FAA and SEI scores (capability, cost, risk, etc.)
Ada leads in MITRE reliability and maintainability comparisons
Why Ada?

Ada Information Clearinghouse
800/232-4211 or 703/681-2466

Defense Information Systems Agency Center for Software

DoD-wide Policy It is DoD policy to use commercial off-the-shelf (COTS) software whenever it meets our requirements. When COTS or NDI software is not available to satisfy requirements and the DoD must develop unique software for which the government is responsible for lifecycle maintenance and support, that software must be written in the Ada programming language.

DODD 3405.1 Ada is the preferred common HOL Based on lifecycle cost, prefer use of: (1) COTS and advanced software technology, when no government modification or maintenance during lifecycle; (2) Ada; (3) DoD-approved standard HOL, if waiver granted Use Ada for all major upgrades (1/3 or more of lines total).

Army extensions: HQDA ltr 25-92-1, 25-95-1 Ada for all modifications of 1/3 or more of functional component SQL is approved for DBMSs 4GLs permitted for prototypes, short-term, ad-hoc systems; non-Ada prototype cannot be fielded.

Navy extensions: NAVINST5234.2A Ada for modification of 1/3 or more of computer software configuration item or sub-system specification, within 5 years Waivers granted only on substantiation of economic analysis.

Air Force extensions: SAF/AQK Action memo Distinguishes exceptions/waivers, gives details on each Exempts individual-use, unique, in-house applications SAF/AQK Info Memo Interprets term "cost effective" in Congressional Ada mandate.

All three Services permit baselined ("project-validated") compilers -- projects can keep same compiler throughout lifecycle (after validation certificate expires).

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