RCM Analysis - Failure Effects (Step 1)

This article describes how to register failure effects in an RCM Analysis, using the first guided step.

The first of the 5 guided steps in IMS covers failure effects. A failure effect describes what would happen if no task were in place to anticipate, prevent, or detect a failure. It answers Question fout of the seven RCM questions: What happens when each failure occurs? (formally, the failure scenario).

What Are Failure Effects?

A failure effect statement describes what would happen if a failure mode occurred. RCM draws a clear line between a failure effect (what happens) and a failure consequence (how much the failure mode matters).

Failure effect statements are used to assess the consequence of each failure mode, and they supply the information needed to decide which failure management policies will avoid, eliminate, or minimize those consequences to the satisfaction of the asset's owners/users.

The main policy options are proactive maintenance tasks — on-condition, scheduled restoration, and scheduled discard — each with an associated frequency. To identify these tasks correctly you must start from a true zero base: assume no proactive maintenance is being carried out, and that the failure mode does in fact cause the functional failure. Describe failure modes and write failure effect statements on that basis.

Note

Completing the failure effects requires input from operations and maintenance, guided by the RCM facilitator. Remember that the degradation you describe assumes no maintenance is applied.

Completing the Failure Effects field

The Failure Effects field is a free-text field describing the physical behavior of the equipment under that failure mode. It follows a cause-and-effect logic that leads to operational consequences across assets, people, and environment.

The editor supports advanced text editing, including object links and embedded images (drawings or photos).

You can either type directly into the field or use the IMS RCM function to insert the default part of the text first.

Using and editing the default text

The Insert default text holds the repetitive part of a failure effects statement; the text specific to each equipment/failure mode is added afterward, once the default has been inserted.

You can create, extend, and edit this default text under Settings > Maintenance > Common Data > Rich Text default. To edit it without leaving your analysis, open a second IMS session in a new browser tab (right-click the link).

The default text structure

The default supplies the a–e scaffold below. The plain text is the reusable prompt; the bold entries show an example for a pressure-control valve.

Function equipment: To regulate the pressure in the reaction section. 

Function item: To move the valve stem 

Spared/ Stand by: By-pass and block valves.

a. Physical behavior of equipment on failure mode. Aging of bladder rubber, Bladder cracks and leaks, Actuator fails, Valve opens in a limited way. Reactor pressure too high, high pressure alarm/ trip.
b. Potential for consequential damage to equipment. No

c. How can the failure be observed? High pressure alarm

(Operators will act on indications in the control room like alarms, video cameras, gas detectors etc. [No observations in field]).

d. What action will the operator take on failure of the equipment?

Production: Reduce throughput to minimum, run over by-pass.
Maintenance: Priority repair of actuator. 

e. What are the production losses or other operational consequences on failure ?

(hours downtime, hours reduced production, HSE consequences).(incl repair)

Production loss: 8 hrs 75%.      Environment:  No   Health & Safety: No

At repair/ restore: is production loss encountered? Yes

Note

The Physical behavior of equipment on failure mode can be written as a sentence describing the P-F curve of the failure mode: where degradation starts, how it develops (any degradation stages), and where it ends (the stable end point).

Finishing the Step

Once every aspect is filled in, the statement should describe what happens when the failure occurs — the physical behavior of the equipment under that failure mode. This is the "no maintenance" situation of the RCM Analysis.

Once you are done, click Criticality Assessment to continue to the next guided step.

Note

The FM Notes field is not used at this stage.

Instruction video

For a walkthrough of the guided steps, see RCM Analysis Guided Steps - Episode 7.