From Guesswork to Governance
How to Build a SaaS Dependency Map That Actually Reduces Risk
Every company depends on far more SaaS tools and cloud services than it realizes. Most of the time this goes unnoticed, because everything works. When it doesn’t, the impact spreads quickly. A login failure triggered by an IdP outage can block every employee from accessing systems. A DNS issue can cripple payments, onboarding, or support channels. Teams usually learn about these dependencies during an incident, which is the worst possible time to discover how the architecture fits together.
A dependency map changes this dynamic. It becomes the foundation of a modern DR and resilience program because it tells you what you rely on, how those pieces interact, and what happens if they fail. It also shows who is accountable and which investments would reduce the most risk. What follows is a practical guide to building a dependency map that is clear enough for executives and detailed enough for engineers, while staying flexible as your environment evolves.
Step 1. Define scope and the objects in your system
Start by choosing how wide you want togo. A good rule is to model across five layers: infrastructure, platforms, applications, third-party services, and the people or processes that support them. This gives you a structure that scales from simple to complex without losing clarity.
Next, capture the relationships. These don’t need to be drawn perfectly on day one.
Begin with the highest-impact flows:
- Login → IdP → DNS → CDN
- Checkout → Payment Processor → Emailor SMS Gateway
- User Support → Ticketing System →Knowledge Base → Status Page
The point is to build a simple, shared mental model. Your first version won’t be precise. That’s fine. Breadth is far more valuable at this stage because gaps become visible early. You can always tune the map later with more accurate dependency chains and service-level detail.
The real aim of Step 1 is to get everyone aligned on what exists and how it connects. Once that picture is in place, teams can shift from assumptions to actual architecture.
Step 2. Tier and score what you depend on
Once the objects and links are laid out, add structure to the risk assessment. For each dependency, capture five data points
- Likelihood of failure
- Impact on revenue, operations, or compliance
- Time to recover if the dependency becomes unavailable
- Existing mitigation paths
- Vendor maturity and historical stability
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A 1 to 5 scale keeps this consistent.Add the numbers together to get a total score between 5 and 25. This score becomes a simple way to prioritize effort. Most organisations quickly spot patterns: a handful of dependencies absorb most of the risk budget, while others matter far less.
At this point, add another dimension:blast radius. Identify how much of your customer base or internal workforce relies on each component. For example, your IdP may support 100 percent of the employee login experience, while your SMS gateway may affect only users in a specific region. Mapping blast radius helps you explain risk in business language and pair risk scoring with journey-critical coverage.
Step 3. Connect contracts, SLAs, and controls
A map on its own is directional; a maptied to evidence becomes operational. Connect each dependency to itscontractual and compliance data. This should include:
- SLA terms covering uptime, support response, RTO, and RPO
- Renewal dates and terminationclauses
- Audit certifications such as SOC 2,ISO 27001, ISO 22301
- Data residency or regulatory commitments
With this information linked, your map becomes a single reference point for resilience, security, and compliance teams. It also becomes far easier to prepare for audits because the controls you rely on are already aligned to frameworks. Map each dependency to NIST CSFRespond and Recover categories and to ISO 22301 expectations. This ensures consistency across teams and helps executives understand where exposure sits.
Step 4. Assign owners and define how you test
Ownership turns documentation into governance. For every Tier 1 dependency - the ones whose failure would meaningfully disrupt revenue, safety, or trust - assign a named business owner.This person is accountable not only during an incident but also for maintaining ongoing resilience.
Create a testing schedule that matches the dependency’s risk profile. Some systems need quarterly tabletop exercises.Others may require annual or semi-annual live tests, especially where failover paths exist. Track:
- Last test date
- Next planned test
- Test method (tabletop or live)
- Issues found and actions taken
Also note the communication steps that must happen when the dependency fails. Include how and when to update your status page, notify internal channels, or escalate to your vendor’s account management team. This ensures that the operational response is just as structured as the technical one.
Step 5. Make the map a living asset
A dependency map loses value quickly if it sits in a presentation deck. To keep it useful, store it where operational work happens: your CMDB, VRM system, or GRC platform. This keeps the map discoverable and connected to change workflows.
Update the map after every incident, major architectural shift, vendor change, or quarterly risk review. This rhythm keeps your resilience posture realistic instead of theoretical.
Finally, publish an executive-friendly dashboard summarising:
- How many dependencies fall into each tier
- The top five risks
- Open remediation items
- Expected completion dates
Executives don’t need the full map.They need to understand exposure, progress, and budget direction. A simple dashboard aligns everyone and makes the map a core governance asset.
Deliverables that actually matter
When done well, a dependency map produces three practical outputs:
- A “critical path” diagram that shows the systems behind your most important customer journeys
- A risk-weighted heat map that guides budget decisions and highlights where resilience investment will materially reduce exposure
- Audit-ready evidence including control mappings, test logs, SLA proof points, and remediation history
These outputs let the map shapedecisions. Until it does that, it remains an interesting diagram instead of a governance tool.
A Five-Day Starter Plan
To help teams get moving without over-engineering the process, use this simple plan:
Day 1: Build a first-pass dependency list for two journeys: User Login and Payment.
Day 2: Tier and score each dependency.Identify at least two fast wins, such as secondary IdP routing, DNS failover, or alternative messaging channels.
Day 3: Add SLA and renewal fields to your vendor records. Complete them for all Tier 1 systems.
Day 4: Assign an owner and define test cadence for each Tier 1 dependency.
Day 5: Publish a one-page executive overview highlighting critical risks and upcoming remediations.
KendraCyber’s view is consistent: resilience is a discipline, not a document. A strong dependency map isn’t the goal. The goal is better decisions, clearer ownership, and faster recovery when something fails. When your map becomes the backbone of your resilience conversations and OKRs, that’s when governance replaces guesswork.