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Parasyn operational technology engineering and consulting
OT Cybersecurity

OT Cybersecurity and Safety-Assured Engineering

Parasyn secures Australian critical infrastructure through IEC 62443-aligned architecture and SOCI Act regulatory alignment, treating cybersecurity as a prerequisite for safety, not an add-on to the network. Delivered across water, wastewater and rail, from preliminary reviews to multi-year design assurance.

3
Engagements, 3 Sectors
2+
Years on the Longest Mandate
IEC 62443
Standards-Aligned Delivery
TS 50701
Rail Cyber Standard Applied

We bridge the gap between corporate cybersecurity and operational technology. We work alongside corporate IT security teams and, as hands-on automation engineers ourselves, we treat plant uptime as a core requirement, not an afterthought, when applying enterprise security policy to legacy control systems.

IEC 62443 Zone & Conduit Design/// SOCI Act Compliance/// Preliminary OT Cyber Review/// Segmentation Architecture/// TS 50701 Design Assurance/// Safety-Security Convergence/// IEC 62443 Zone & Conduit Design/// SOCI Act Compliance/// Preliminary OT Cyber Review/// Segmentation Architecture/// TS 50701 Design Assurance/// Safety-Security Convergence///
Capabilities

OT Cybersecurity Capabilities

Parasyn's cybersecurity practice is built around IEC 62443 security architecture and Zone/Conduit design, segmenting legacy OT assets from IT and enterprise networks without disrupting the deterministic control loops that must keep running. The same practice supports SOCI Act compliance for boards and directors carrying increased liability for critical infrastructure risk.

01
IEC 62443 Security Architecture
Zone and Conduit design, network segmentation and hardening.
02
SOCI Act & Regulatory Resilience
Compliance auditing, risk assessments, CIRMP evidence.
03
Preliminary OT Cyber Security Review
Fast, non-intrusive discovery assessment producing a phased, prioritised roadmap.
04
OT Segmentation Architecture Design
Vendor-grounded Zone/Conduit design for the platforms actually installed, not a generic pattern.
05
Cyber Design Assurance (Owner's Engineer)
Independent review enforcing traceability from risk to requirement to verified test result, aligned to standards such as TS 50701.
06
Lifecycle Currency as a Risk Control
Patch, firmware and platform-version management treated as part of the OT security posture, not a separate maintenance concern.
Track Record

Track Record

Three engagements, three different roles: a preliminary review, an architecture redesign, and an ongoing design-assurance mandate, across water, wastewater and rail.

Regional Council
Water & Wastewater
Preliminary Review
A Practical First Step Toward OT Cyber Resilience
A six-week, non-intrusive discovery review across 10 focus areas turned scattered OT security practice into a three-phase roadmap the council could act on immediately, surfacing that the IT team had a solid server inventory but no visibility of the PLCs, RTUs and field instruments the treatment team actually ran.
6 wks
Engagement
10
Focus Areas
3
Roadmap Phases
Read the case study →
Regional Water Utility
Segmentation Design
Architecture Redesign
When a Textbook Design Fails the Real World
The incumbent Tier 1 consultancy's standards-perfect historian segmentation design was never built: it assumed capabilities the installed platform didn't have. Parasyn evaluated three candidate architectures against the vendor's actual constraints and delivered a dual-historian design the utility could use.
6 mo
Engagement
3
Architectures Evaluated
2
Stakeholder Workshops
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Passenger Rail Operator
Owner's Engineer
Design Assurance, Ongoing
Why the Right Question Is Better Than a Thousand Review Comments
As Owner's Engineer on a major traction power and signalling replacement, Parasyn has guided the design contractor's TS 50701 cyber security documentation, threat log, risk assessment, zones and conduits, requirements and test plan, to show a traceable line from risk to verified test result, not just a plausible narrative.
2+ yrs
Ongoing
5
Core Artefact Types
TS 50701
Standard Applied
Read the case study →
From the Rail Owner's Engineer Mandate
The Standing Question Behind Every Review
Risk
Identified in the threat log and risk assessment
→
Requirement
A specific control in the requirements matrix
→
The Usual Gap
Documented in prose, not proven by a test
→
Verified Test Result
The only evidence Parasyn accepts as closed
A design contractor can produce a thousand pages of documentation and still not close this chain. Parasyn's role as Owner's Engineer is to keep asking whether a given risk can actually be traced through to a verified test result, sending work back to the gate when it can't, rather than letting volume stand in for proof.
Convergence

Safety-Security Convergence

Parasyn's view, set out in Bridging the Execution Gap in OT Cybersecurity, is that OT security and functional safety can't be treated as separate disciplines. Where Functional Safety Meets OT Cybersecurity and its companion piece on SIL 2 design for tunnel ventilation control systems both work through this in a real systems-engineering context: cybersecurity as a precondition for a safety case to hold, not a bolt-on control.

Partner

Why Partner with Parasyn

Cybersecurity at Parasyn isn't a separate practice. It's covered by the same company-level TAO accreditation and IEC 62443 certification as every other Parasyn engineering discipline, and delivered by the same RPEQ/RPEV registered engineers who do Parasyn's other work. The track record above is the proof: a council whose IT team couldn't see its own pumps, a utility whose textbook design a Tier 1 consultancy couldn't actually build, and a rail operator that needed someone to keep asking whether a risk was really traced to a test result.

Ready to Talk OT Cybersecurity?

IEC 62443 alignment, SOCI Act compliance, or a rail-grade design assurance mandate: start with an engineer, not a sales rep.

Talk to an OT Security Specialist
The Evidence

Related Capability & Thinking

Solutions

Articles

Case Studies

Lifecycle Management