Introduction

Most teams have a lot of dashboards and not nearly enough shared understanding.

You can have world‑class observability, real‑time alerting, and beautifully designed SLO views—and still keep tripping over the same kinds of incidents. Numbers and charts are necessary, but they don’t always translate into a common mental model of how your system actually fails.

Enter the pencil‑and‑string incident map: a deliberately low‑tech, tactile way to visualize emerging production risks. Think of it as a physical radar for your system, something people can literally stand around, point at, and argue about.

This approach doesn’t replace your tools. It complements them by creating a shared space—on paper, with strings and sticky notes—where engineers, product managers, and non‑technical stakeholders can collaboratively explore how incidents relate to reliability goals, tech debt, and the passage of time.

What Is a Pencil‑and‑String Incident Map?

At its core, the map is a big physical diagram of your system and its risks.

You typically start with:

• A large sheet of paper or whiteboard
• Pencils/markers for drawing systems and boundaries
• Strings or yarn to connect related incidents
• Sticky notes or index cards to represent incidents, near‑misses, and risks

From there, you create a radar‑like layout:

• The center might represent your core system or primary product surface.
• Rings move outward to represent either time, system distance, or risk severity.
• Sectors can represent functional areas or services (e.g., checkout, auth, data pipeline).

Each incident or near‑miss becomes a card on the map. Strings connect events that share a root cause, dependency, or reliability goal. Over time, the board becomes a tactile, visual history of how your system fails and where it’s drifting out of tolerance.

The point is not precision; it’s conversation.

Why Go Low‑Tech in a High‑Tech Environment?

It’s easy to ask: why bother with paper and string when you can have a graph database, a service map, and real‑time traces?

Because how we represent information shapes how we talk about it.

1. Slowness drives depth

When people have to write by hand, place a note, and tie a string, they’re forced to slow down and think:

• Where did this really start?
• Who did it affect?
• What else is connected to this?

This friction is good. It leads to richer questions and fewer hand‑wavey explanations.

2. Everyone can participate

Most risk dashboards are optimized for people who:

• Know the tools
• Know the data model
• Know the terminology

A pencil‑and‑string map lowers the barrier. If you can read, write, and point, you can contribute. Product managers, support staff, and even executives can help:

• Identify blind spots (“We keep ignoring this partner integration.”)
• Connect incidents to business impact
• Challenge assumptions about what’s “acceptable” risk

3. It creates a shared focal point

A big board on the wall is a physical gathering place. People can:

• Stand side‑by‑side
• Disagree constructively
• Use gestures and spatial references (“This area is getting crowded.”)

That kind of embodied, shared focus is much harder to achieve when everyone is just screen‑sharing metrics.

Mapping “Time‑Zero” and “Aging” Risks

One of the most powerful aspects of this radar is its ability to surface two distinct risk types:

1. Time‑zero risks – issues baked into design, deployment, or process from the start.

   • Example: A service that launched without rate limiting.
   • Example: A deployment process with no automated rollback.

2. Aging risks – issues that accumulate as the system runs.

   • Example: Tech debt in a critical library no one wants to touch.
   • Example: Config drift between environments.
   • Example: “Temporary” manual runbooks that never got automated.

On the map, you can visually differentiate them:

• Use different colors of sticky notes or pens.
• Place time‑zero risks closer to the origin of features or services.
• Place aging risks near the edges, where things start to fray.

Over time, patterns emerge:

• Clusters of time‑zero risks in a particular team’s launches.
• Pockets of aging risk around certain legacy services.
• Areas of the system where incidents are increasingly driven by drift and neglect rather than new features.

This lets you ask better questions:

• Do we need better design reviews or launch gates?
• Where are we under‑investing in maintenance and refactoring?

Making SLOs and Error Budgets Story‑Driven

Most SLOs and error budgets are communicated as numbers:

• 99.9% availability
• < 1% request error rate
• P95 latency < 250ms

Important, but abstract.

The incident map lets you connect those numbers to stories.

Here’s how:

1. For each incident or near‑miss, note which SLO(s) it touched.
2. Use string to connect the incident card to a section of the board representing that SLO.
3. Optionally, annotate with simple tags like:
   • “Burned 30% of error budget in 2 hours”
   • “Customer‑visible impact in EU region only”

Over time, you’ll see:

• Certain SLOs surrounded by strings and incident cards—clear hotspots.
• Other SLOs that rarely get touched—perhaps too conservative or not very business‑critical.

This transforms SLOs from abstract SLIs into narrative anchors:

• “We’re not just missing the 99.9%. This cluster of incidents is why checkout reliability feels fragile right now.”
• “We’ve burned this error budget three quarters in a row for the same underlying dependency.”

That story‑driven framing is much easier to discuss with non‑technical stakeholders and makes prioritization conversations more grounded.

Turning the Map into a Living Artifact

A one‑time workshop is nice. A living map is powerful.

The magic happens when you update the map regularly:

• After incidents and near‑misses
• During post‑incident reviews
• As part of game days or chaos exercises

Each session, you:

1. Add new incidents.
2. Connect them with string to:
   • Related past incidents
   • Relevant SLO sectors
   • Known aging risks
3. Mark mitigations and improvements directly on the map.

Over months, the board evolves into something like a hybrid of playbook, runbook, and risk register:

• You can see which areas you’ve actively hardened.
• You can spot recurring failure patterns.
• You can trace how your architecture and risk profile have changed.

Teams new to an area can learn faster by walking the map:

“Here’s where we used to have cascading retries, here’s how we refactored it, and here’s where we’re still nervous about load spikes.”

The map becomes a shared institutional memory, not trapped in a few people’s heads or scattered across docs.

A Simple Facilitation Pattern

You don’t need a big process to get started. Here’s a lightweight pattern for a 60–90 minute session.

1. Set up the radar

• Draw sectors for key domains (e.g., Auth, Payments, Infra, Data).
• Mark rings for time (e.g., last month, last quarter, last year) or risk severity.
• Reserve space for SLOs or key reliability goals.

2. Gather raw material

Ask participants to bring:

• Recent incidents (last 3–6 months)
• Near‑misses that never hit a formal severity level
• Known worries: “Things that keep you up at night”

Each becomes a note with:

• Short title
• Date
• Impact summary
• Suspected or confirmed cause

3. Place and connect

As a group:

• Place each card in the sector and ring that feels right.
• Use string to connect:
  • Related incidents
  • Incidents to SLO areas
  • Incidents to known aging risks

Encourage discussion: why are we placing it here, and what does this connection mean?

4. Identify themes and candidates for action

Step back and look at the map:

• Where are the clusters?
• Which sectors are empty (maybe under‑observed)?
• Which SLOs are dense with connections?

From this, derive a small set of concrete bets:

• A specific automation investment
• A particular refactor or redesign
• A new review or launch gate to reduce time‑zero risk

Capture these decisions near the map so anyone walking by can see the link between incidents → risk patterns → investments.

Using the Tactile Radar to Guide Risk Reduction

When you repeat this process, the map starts directly informing where you invest:

• Automation: areas with lots of manual runbook steps or repeated human error.
• Hardening: services that act as blast‑radius amplifiers in multiple incidents.
• Design changes: core flows where time‑zero risks keep reappearing (e.g., lack of idempotency, unsafe defaults).

Instead of treating incidents as isolated events, you’re using them as data points in a shared, visual risk landscape. The tactile nature makes trade‑offs more tangible:

• “If we don’t invest here, this cluster is likely to grow.”
• “We’ve added three strings to this SLO and made no structural changes.”

This is what turns incident reviews and game days from ritual into intentional risk management.

Conclusion

The pencil‑and‑string incident map is intentionally simple:

• No fancy tools
• No complex data pipelines
• No perfect modeling

And that’s exactly why it works.

By slowing people down, bringing them together around a shared physical artifact, and making risk visible as a landscape instead of a spreadsheet, you unlock deeper conversations and clearer priorities.

Over time, your tactile radar becomes a living record of how your system fails, learns, and evolves—a complement to your observability stack that strengthens not just reliability, but also team alignment and learning culture.

If your incident reviews feel flat or your SLOs feel abstract, try grabbing a big sheet of paper, some string, and a handful of sticky notes. You might be surprised how much risk becomes visible once you can literally reach out and touch it.