Instabug calculates an Apdex score that reflects the performance of your Flows. An Apdex score ranges between 0 and 1; the higher the value, the better the performance:

• Apdex score ≥ 0.94 equates to Excellent performance.
• Apdex score ≥ 0.85 and < 0.94 equates to Good performance.
• Apdex score ≥ 0.7 and < 0.85 equates to Fair performance.
• Apdex score ≥ 0.5 and < 0.7 equates to Poor performance.
• Apdex score < 0.5 is considered Unacceptable.

The following color-code criteria is also applied:

How is the Flow Apdex calculated?

There are two factors that affect the apdex of a Flow: flow latency, and drop-offs.

Flow Latency

When a completed occurrence of a Flow is collected from the SDK, it is flagged based on the target duration (T) for that Flow. A Flow occurrence is considered:

• Satisfying: if its duration ≤ T
• Tolerable: if its duration > T and ≤ 4T
• Frustrating: if its duration > 4T

Drop-Offs

If the occurrences was a drop-off (and therefore doesn’t have a completion time), we then consider the reason for the drop-off. A Flow occurrence is considered:

• Frustrating: if the drop-off reason was a Crash, User Termination, Fatal ANR, or Fatal App Hang
• Neutral: if the drop-off was due to user abandonment or the flow timing out in the background.

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Neutral occurrences don’t affect the Apdex of a Flow in any way.

Apdex Calculation

The Apdex score for the entire flow is then calculated as follows:

• Apdex score = (Satisfying occurrences + 0.5 * Tolerable occurrences) / Total occurrences
  • Where: Total occurrences = Satisfying occurrences + Tolerable occurrences + Frustrating occurrences

For example, if a Flow had 5 satisfying occurrences, 3 tolerable occurrences, 2 frustrating occurrences, and 1 neutral occurrence, we discard the neutral occurrence and calculate the Apdex as follows:

Apdex score = (5 satisfying occurrences + 0.5 * 3 tolerable occurrences) / 10 total occurrences = 0.65

How to control a specific Flow's target?

By default, the target for all Flows is set to 0.5 seconds; however, you can easily change this number from your dashboard by clicking on the target highlighted next to each Flow or inside the flow details page.