Service Backlog and Clearance Calculator

Worked example

An agency processing claims after a disruption can track arrivals, completed work and cancellations. Separate an empty queue caused by completion from one reduced by withdrawals.

Start with 20 requests and process three intervals with different arrivals and capacity. The queue first empties in interval two. New arrivals leave two requests at the end of interval three.

Try it yourself

The calculator opens with the fictional example already filled in. Change one input, choose Calculate locally, and compare the result to the original values below. Use Reset fictional fixture to start over.

An unknown result means the available inputs do not support a value. Check the calculator’s Warnings tab for what is missing or uncertain.

Requests completed 64 requests
Requests withdrawn before service 0 requests
Final backlog 2 requests
First interval ending with an empty queue 2 interval
Largest closing backlog 15 requests

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Calculator

Approach (label only)Changing the label does not improve capacity, speed, error rates or confidence. Enter measured differences explicitly.

Comparison conditions and human review

Equal-resource comparison conditionsRecord budget, staffing, resources, information release dates, scenario conditions and evaluation criteria. Material differences can make options not comparable.

Evaluation period

Geography / exercise boundary

Human reviewers and roles

This evaluation depends on a real transaction

Supplied human authority gateThis declaration is not legal certification. Blocked, pending or assumed gates stop transaction-dependent evaluation.

Keep units consistent within each table. Enter zero when the amount is known to be zero. Leave optional amounts blank when they are unknown. If a required value is missing, the calculator will ask for it.

Advanced: complete input envelope and optional fields

Edit optional fields using the method dictionary. Apply validates and recalculates the entire input. Unknown values remain null.

Versioned input JSON

Import local JSON or CSV

Files stay in this browser. Maximum 1 MiB. JSON imports are recalculated. CSV supports flat observation tables, with column types taken from the displayed fixture. Empty cells become null.

Workbench JSON / input envelope

CSV target table

CSV file, matching the target table headers

Compare the arrangements

Keep physical resources and evaluation conditions equal. With identical inputs, all three approaches produce identical arithmetic. The comparison refuses material differences in declared conditions; it does not verify those declarations.

Show only differing metric rows

Privacy: comparison inputs may contain sensitive notes or operational details. Storage is off by default. Do not enter personal records or sensitive infrastructure details. Reproduction exports include supplied inputs and notes, including raw small-cell inputs suppressed from CORE-009 result tables. Suppression of displayed results does not make a reproduction export safe to publish.

Save comparison inputs on this device until I clear them

Executive brief and reproducible export

Public exercise notes

Review for personal, confidential or sensitive material before saving or sharing. No automatic submission occurs.

Read the generated brief

Method, inputs and limits

Track a service queue as new requests arrive and declared processing capacity changes. Method version 0.2.0. Estimate individual waiting times, predict abandonments, or model priorities and retries.

CORE-019 input dictionary
Input	Unit / type	Required interpretation
opening — Opening backlog	requests / number	Whole requests waiting before the first interval.
periods — Ordered service intervals	requests per interval / number	Each row has arrivals and capacity. Optional withdrawn is the number of documented cancellations or abandonments before service.

Visible mathematics / decision rules

Completed = min(opening backlog + arrivals − withdrawn, capacity).

Closing backlog = opening backlog + arrivals − withdrawn − completed.

What this result cannot establish

One queue with homogeneous requests. Enter arrivals and withdrawals that occurred before processing, or split the interval.
Queue clearance means an interval ends at zero. Withdrawals may clear a queue without completing the work.

What would falsify the assumptions?

Reconcile opening requests, arrivals, completions and closing requests against the service log.
Assumptions fail if the supplied definitions, units, period, scope or source records are wrong or incomplete.
An independent source audit or replication may contradict an input or the recorded dependency.
This method creates no resources. Physical conservation is checked in the inventory and transfer ledgers; descriptive graphs and checklists are not resource-flow models.
The same equations and review checklist can be reproduced with a spreadsheet or structured human-only process.
This is deterministic arithmetic, a descriptive comparison or a structured governance check, not a fitted causal effect or forecast. Fictional inputs remain an exercise.
Equal or worse measured errors, net review effort, disclosure burden or fallback under MAR would show no added benefit or added risk; no improvement is assumed.

Reproducible fictional fixture and independently calculated expectations

This fixture is synthetic. It does not describe a country, government, company or event.

{
  "observations": {
    "unit": "requests",
    "origin": "synthetic",
    "sources": [
      {
        "id": "SYN-019",
        "kind": "synthetic",
        "label": "Fictional continuity exercise",
        "url": null
      }
    ],
    "opening": 20,
    "periods": [
      {
        "arrivals": 30,
        "capacity": 35
      },
      {
        "arrivals": 10,
        "capacity": 30
      },
      {
        "arrivals": 6,
        "capacity": 4
      }
    ]
  },
  "parameters": {}
}

Expected checks

{
  "completed": 64,
  "closing": 2,
  "firstClearInterval": 2,
  "peakClosing": 15
}

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Authoritative background references

NIST: Cybersecurity Framework 2.0 — Outcome taxonomy, not a calculated national risk score. Reviewed 2026-11-09. Reference, not endorsement or validation.

These sources inform definitions or review practices. They do not validate this implementation or endorse MAR.

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