Presenting a Case study on Software Verification & Validation (IV&V) for a subsystem of a Defence Helicopter. The IV&V was carried out in accordance with the RTCA DO178B DAL B guidelines. With over 2 decades of strong experience, Oaksys was chosen to carry out the full lifecycle IV&V of the said subsystem. This is one of many such projects where Oaksys was responsible for conducting software IV&V and Testing.

1. AVIONICS CASE STUDY –
IV&V OF STANDBY ENGINE INSTRUMENT (SEI)
Oak Systems Pvt. Ltd.

2. Main features of the System
❖ SEI is a subsystem of Advance Light Helicopter (ALH) as a standby unit
❖ Safety critical embedded software system with –
❖ Night vision capability
❖ Digital display
❖ Fault logging for ground examination
❖ It displays engine parameters such as
❖ Q[Torque]
❖ delta Q [Delta torque]
❖ NF [Engine free turbine RPM]
❖ TGT [Turbine gas temperature] and
❖ Cautions & Warnings
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3. Trigger for IV&V
As per DO-178B guidelines Independent Verification &
Validation (IV&V) is mandated
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4. H/W Abstraction Layer
Architecture
APPLICATION
DEVICE DRIVERS
SUB-APPLICATION
WDT MEMORIES
Oaksys Scope S/W
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5. Scope of Work
To Conduct IV&V as per RTCA - DO178B Level B compliance -
❖ Planning phase docs review e.g. PSAC, SVP, SDP, SCMP, SQAP
❖ High level Requirement Verification
❖ Low level Requirement (Design) Verification
❖ Code Evaluation (MISRA Standards)
❖ Requirement based test case preparation (High level and Low level Tests) for 100%
Requirement coverage
❖ Source Code Coverage (100 % Statement, 100 % Decision)
❖ High Level and Low level Test Execution (using LDRA tool)
❖ Traceability analysis:
▪ Requirements Design Code
▪ Requirement High level Tests
▪ Design Low level Tests
❖ Software Configuration Audit
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Software Size: 9KLOC
Language: C

6. Accomplishments
❖ Provided templates and checklists meeting DO178B guidelines
❖ Thorough plan document review with emphasis on safety measures needed as a suggestion
❖ Requirement and design review : Uncovered anomalies in the document in form of
traceability, completeness and correctness w.r.t to DO-178B standards
❖ Test case creation at both HSI and Unit level with emphasis on uncovering faults to make
system robust by adopting testing techniques like BVA, Equivalence partitioning, arithmetic
precision, fault recovery
❖ Test case execution at both levels with emphasis on 100 percent requirement coverage, 100
percent branch coverage
❖ Data coupling and control coupling adherence checks
❖ Multiple versions of software subjected to test, based on review by the regulators
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7. Outcome
Activity/Task Status
Review Plan Docs:
PSAC, SDP, SCMP, SRS, SDS, SCS, SQAP, SVP
Delivered
SRD Review
Delivered
HLR SVCP Preparation
Delivered
SDD Review
Delivered
LLR SVCP Preparation
Delivered
Code Review
Delivered
SDD-Code Traceability
Delivered
LLR Test Execution
Delivered
HLR Test Execution
Delivered
IVV Reports (SCI, SECI, SAS)
Delivered
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8. Thank you!
Oak Systems Pvt. Ltd.
#27, NGEF Lane, Off 100 Feet Road,
Indira Nagar, Bengaluru – 560 038, INDIA
Tel : +91-80-4126 7681
Email: contact@oaksys.net
URL: www.oaksys.net
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