What are cause & effect matrices?
A cause & effect matrix defines exactly how a system responds to every event. Causes, such as a detector, manual call point, sprinkler flow switch or fault condition, run down one side; effects, such as sounders, voice messages, smoke control, door releases, lift recall, plant shutdown and signals to other systems, run across the other. Each intersection states what should happen. It is the single reference that designers, installers, commissioning engineers and witnesses all work from.
What's included
- Every cause and effect, organised by zone, area or system
- Clear definition of each output and the interfaces to other systems
- Phased or delayed actions where the design requires them
- A format ready to drive commissioning and IST narratives
- Revision control, so everyone works from the current version
How EJH produces cause & effect matrices
We develop the matrix from the design intent, the fire or operational strategy and the interfaces with every connected system, then review it with the stakeholders who own those systems. Once agreed, it becomes the source we build commissioning and IST narratives from, so testing proves exactly what was designed.
What it means for your project
- Every interface between systems is defined before installation, not discovered on site
- Designers, installers and commissioning teams work from one agreed reference
- Commissioning and integrated testing are faster and more complete
- A clear record for handover and for the building's life
Frequently asked questions
What is a cause and effect matrix?
A cause and effect matrix is a table that defines how a system responds to every input, showing which outputs operate for each cause. It is widely used for fire detection and alarm systems and the building systems they interface with.
Why does it matter for integrated testing?
Integrated systems testing proves the responses defined in the matrix. A complete, accurate matrix means testing covers every interface and the results can be checked against an agreed reference.
Can you update an existing matrix?
Yes. We can review and update an existing matrix to reflect design changes, then carry those changes through to the test documentation.