Agile development of safety critical systems

NOTES ON AGILE AND
SAFETY-CRITICAL
DEVELOPMENT
Jaana Nyfjord
jaananyfjord
jaana@sics.se
In close collaboration with
Efi Papatheocharous (SICS)
Jakob Axelsson (SICS) & Martin Törngren (KTH)
Source: http://www.usaid.gov/ via Wikimedia Commons: http://commons.wikimedia.org/wiki/File:Coral_Reef_in_the_Red_Sea.JPG
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AGILE BEYOND SOFTWARE
CHALLENGES
• Language
• Organisation & teams
• Process synchronisation
• Ownership, e.g testing
• Lifecycle & time-spans
• Scalability
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SOLUTIONS
• Integration points
• Product architecture views
• Kanban
• Demos
• Communication system
• Tools
• Cyclic hardware development
AGILE & SAFETY
CHALLENGES
• Quality not the same as safety
• Method applicability
• Contradictory principles SOLUTIONS
• Education
• Prescriptive standards
• Close cultural gap/mindset
• Architecture ”meet in the middle”
• Close collaboration w assessors
• Language
• Goal-oriented safety standards
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NOW, CONCLUDING REMARKS
• …
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Waterfall
Few risks, sequential,
late integration and testing
DO-178C
MIL-STD-1521
Low ceremony
High ceremony
Compliance, traceability
Value
SCRUM
XP
Iterative
Risk-driven,
continuous integration and testing
Nyfjord & Hedegård, 2005
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AGILE LEAN DEVELOPMENT OF
SAFETY-CRITICAL SYSTEMS ALDES
•
CHALLENGE ALDES faces the challenges on ever increasing complexity and diversity of safetycritical cyber-physical systems (CPS) and aims to develop a common methodology – a collection of
practices – to overcome them.
•
SOLUTION The theories behind Agile and Lean methods will be used to construct the ALDES
framework for efficient development of safety-critical CPSs.
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OBJECTIVES/SCOPE ALDES considers the special attributes of safety-critical CPSs.
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Compliance: The practices are developed to ensure the compliance of standards and
regulations when Agile and Lean methods are applied.
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Speed: Practices for continuous verification, validation and certification are developed to
locate faults early, to eliminate the need for re-design and to minimize the burden caused by
these activities in the end of the product development
•
Collaboration: ALDES takes into account the different stakeholder interfaces present during
product development processes and takes customers and suppliers closely into the process.
•
MAIN DELIVERABLES
ALDES Methodology
ALDES Knowledge Repository
ALDES Tools
ALDES Measurement Methods
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ALDES – CONSORTIUM
Total : 45 partners
Finland: 12
Spain: 9
France: 4
Sweden: 4
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Italy: 4
Netherlands: 3
Portugal: 2
Serbia: 2
Denmark: 2
Belgium: 1
UK: 1
Greece: 1
COMPLEX ADAPTIVE SYSTEMS
(CAS)
 Complex adaptive systems is derived from the mathematical science of complexity.
 Complex adaptive systems are non-linear, open, dynamic.

In non-linear systems the value of the whole cannot be determined by the sum of the parts

Open systems interact with its environment, receiving inputs and providing outputs, but
doesn’t control it

A dynamic system changes and evolves its behavior in response to its inputs
 Order emerges through the interaction among the system’s parts as they evolve
(within the larger system) in response to the changing environment.
 Hence, CASs are composed of autonomous agents that seek to maximize some
measure of fitness by evolving or adapting to changes as they occur.
 Local, often simple, rules guide the interaction among the agents and result in the
system’s global behavior.
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Q&A
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