Cause and Effect Matrix Template
A cause and effect (C&E) chart for interlocks and SIS logic. Define up to eight effects, then mark X where each cause triggers an effect. The sheet counts effects per cause and checks for causes with no effect.
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- How to Use sheet with steps
- Template sheet, blank and ready
- Example sheet, filled in
- 42 built in formulas
- A4 landscape print setup
- Works in Excel, Google Sheets and LibreOffice
Preview of the Filled Example
This is the Example sheet from the download, so you can see exactly how the completed cause and effect matrix looks.
Effects (columns of the matrix)
| Effect | Tag | Action | Description |
|---|---|---|---|
| E1 | XV 4101 | Close | Tank inlet shutdown valve |
| E2 | P 401 | Stop | Transfer pump |
| E3 | XV 4105 | Close | Tank outlet valve |
| E4 | BV 1101 | Close | Burner fuel valves |
| E5 | BL 101 | Stop | Combustion air blower |
| E6 | AL 01 | Sound | Control room horn |
Matrix: mark X where the cause triggers the effect
| No | Cause tag | Cause description | Set point | Unit | Voting | E1 | E2 | E3 | E4 | E5 | E6 | E7 | E8 | Effects |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1 | LSHH 4103 | Tank high high level | 11.2 | m | 1oo1 | X | X | 2 | ||||||
| 2 | LT 4102 | Tank low low level | 0.8 | m | 1oo1 | X | X | X | 3 | |||||
| 3 | PT 1101 A/B/C | Steam header pressure high high | 14.5 | bar g | 2oo3 | X | X | X | 3 | |||||
| 4 | BSL 101 | Flame failure | 1oo2 | X | X | 2 | ||||||||
| 5 | HS 100 | Emergency stop push button | 1oo1 | X | X | X | X | X | X | 6 |
About the Cause and Effect Matrix
The cause and effect matrix is the simplest way to describe interlock and safety logic so everyone can review it: process engineers, operators, instrument engineers and the SIS programmer. Each row is an initiating cause, each column a final action, and an X joins them.
How to fill in this template
- List the effects (final elements and alarms) in the first table: E1 to E8.
- Enter each cause with its tag, description, set point and voting.
- Put X in every effect column the cause must trigger.
- Check the Effects column: CHECK means a cause has no effect assigned.
- Review with process, instrumentation and safety, then use it as the basis for SIS logic testing.
What the formulas do
- Effects per cause = COUNTIF of X across E1 to E8; shows CHECK when zero.
- Causes without any effect are counted at the bottom.
Related tools
Frequently Asked Questions
What is a cause and effect matrix?
A chart that shows which shutdown actions (effects) are triggered by which initiating events (causes) in a safety or interlock system.
What does 2oo3 voting mean?
Two out of three sensors must reach the trip value before the effect happens, which balances safety and spurious trips.
Is the C&E enough to program the SIS?
It defines what must happen. Timers, resets, bypasses and first out logic are usually described in a separate narrative.
Learn more on the blog
Cause and effect matrix in safety systems explained
A practical guide on instrumentationblog.in that explains the procedure behind this template and how engineers apply it on real plants.
Read Full Article