Celsius Tech Bass Ch 15 Lecture by a team from

Introduction CelsiusTech was a leading Swedish defense supplier – Owned by Saab AB Main product line was Ship System 2000 (Mk3) Typically 1 to 1.5 million lines of Ada running on 30 to 70 processors Differing operator displays, hardware, and presentation languages Sensors and weapons + interfaces vary Runs on OS2000, AIX, POSIX, Ultrix

Product Schedules

Code Reuse

Requirements and Qualities Product line architecture SS2000 Qualities – Performance: Real-time – Modifiability: replacement of weapons/sensors, etc. – Safety, reliability, and availability – Testability: isolate errors quickly.

Physical Architecture

Process View Multi-processing – Each CPU runs several Ada programs – Up to 300 programs total Message Interface – Strong typing – Components are independent Interprocess communication – Processes can run on any processor – Ada tasks for multithreading

Process View – Data Production Data is sent only when altered Data is presented as OO abstractions A component owns a given piece of data All data is accessible by all parts of the system Data is distributed Long-term data is kept consistent Data is checked for errors before being sent out

Process View

Layered View

Module Decomposition View System function groups – Assignment for a particular development team – Each has its own requirements spec. – Consist of system functions Software that implements some requirements – 30 groups, each with ~20 functions

Applying the Architecture Architecture as the Foundation Maintaining the Asset Base as New Systems are Produced Maintaining Large Pre-integrated Chunks Parameterized modules1`

Summary CelsiusTech became a vendor of COTS naval systems Architecture achieved “conceptual integrity” Architecture evolve during validation Overall a successful turnaround from a one-at- a-time to a product line