And the updated projectplan.

Projectplan_RCM_Case_Study_Cooling_Fan_System.ppt (504 Kb, 94 downloads)

Good stuff Rogier. I will make some comments soon

Rogier - well done - just some comments from my end.

I would write for the following FMs (just makes it easier to read)
10A : Switch fails open
10B : Switch fails closed
12A : Switch fails open
12B : Switch fails closed

13A - not automatic shut down - I think the vibration sensor indicates amplitude prompting operator to manually shut fan down (Steve?)
Therefore
13A To sound alarm in control room if vibration exceeds x?mm/s.

16A I disgree that this failure mode will not affect fan system. In worst case fan will fall apart and we have to take it to this level.
Sure we can say a little corrosion may not affect it short term but within the context of RCM and preserving its functions the advent of any corrosion I am sure will cause some effect - may even be secondary eg. corrosion dust finding its way into motor.
I know Steve alluded to the fact there was no corrosion protection referred to on the case study however one would assume in a coastal environment metal would be exposed to salt air in some way especially if it is being drawn through the system.


just my 2c

Mike.

This message has been edited. Last edited by: mike66,

Some comments / suggestions

1B4 Cant see how "tacho register incorrect speed" results in less air flow. Tacho does not do anything except alarm when RPM < 200.
3 - To convey driving force to the fan – is redundant as noted. I think it should be removed as a function.
8A1 failure mode would be rubber cones wear. The rubber provides the dampening.
9A1 – locking pin not installed or incorrectly installed.
11 – there is no indication of RPM. Only alarm if <200.
13B1 – tacho fault will not shut down fan. Tacho is only alarm.
16. I suggest this function be dropped. There is no corrosion protection. Sure corrosion can and will occur but it will result in loss of some other function. IMHO there is no need to list this as a function as to the external person, the function indicates that there is some corrosion protection.

Also, all the malfunctions of the protection that shut down the fan should not be listed against other protection functions. Just gets messy. I suggest we list the failure modes against the primary function.

Keep up the good work.

Rgds
Steve

quote:

13A - not automatic shut down - I think the vibration sensor indicates amplitude prompting operator to manually shut fan down (Steve?)
Therefore
13A To sound alarm in control room if vibration exceeds x?mm/s.

Mike, the vibration switch is a simple spring device that vibrates. If the vibrations are large the contacts mate and the fan shuts down. There is no means to determine what the vibration amplitude needs to be. It works or it dont.... it gets interesting when we try to determine how we maintain it - but that comes later.
Rgds
Steve

Updated Information worksheet V4 posted as a result of comments from Steve and Mike (thanks).

Note: I renumbered the sheet because of deleted records

Please let's move on to Failure Effect

RCM template V4

Regards,

Rogier

Information_Worksheet_V4.pdf (41 Kb, 59 downloads)

And the excel sheet V4

rcm2_template_V4.xls (94 Kb, 55 downloads)

Quick question on effects, well, not quick, example first:
Our work typically uses 3 levels of effects:
Local: (actual failed part; (hose) worn/ abraded/ chafed to the point of leaking).
Next higher: (system/ function/ process) fluid loss to the point of depletion/non-function; no longer cooling), motor sizes, conveyer stops.
End effects: (impact to plant/ business) Production loss, Item stops until motor is replaced >4 hours, additional damage to adjacent systems, hazardous oil spill < 50 liters/ smoke and fumes, possible major injury.

Now, what kind of story will we tell in the effects block?

The level of describing the failure effect depends whether it includes all information needed to support the evaluation of the consequences of the failure (decision diagram).

The effect of the failure should be described as if nothing was being done to prevent it.

The following should be recorded:

• What evidence (if any) that the failure has occurred
• In what ways (if any) it poses a threat to safety or environment
• In what (if any) it affects production or operations
• What physical damage (if any) is caused by the failure
• What must be done to repair the failure

In this case Revenue loss of $5000 per hour if one system down for > 30 min
Down time, what to do and repair cost is important to decide in the next step in it's technically feasable and worth doing.

Updated projectplan V4

Projectplan_RCM_Case_Study_Cooling_Fan_System.ppt (506 Kb, 50 downloads)

12 A 1 To shut down the fan in the event of abnormal vibrations Unable to shut down the fan in the event of abnormal vibrations
B 1 Fan stopped while no abnormal vibrations occured
Guys,
If the fan stops as in 12 B 1 then the function has not been lost. If this failure mode is going to be listed,I would think it goes against Function 1 which is to supply the air.
Rgds
Steve

Some suggestions...
1A6 - FM Broken belt - suggest "fan belt fails due to wear".
1B1 &2 - these failure modes will result in zero flow fairly quickly. Suggest they be allocated against the zero case.
1B3 "locking device failure" is a hidden failure because the failure on its own, will not result in lost production. This one needs to be moved.
14A1... the failure modes of the tacho are that the magnetic pulse generators fall off the shaft or the pick ups' mounting bolts come loose and the pick ups position moves away from the shaft and no signal is picked up. Other faults are attahed to the wiring and electronics.
Rgds
Steve

Seems we have the classical RCM problem.... the project is stalling! What is happening guys? Everyone losing interest?
Rgds
Steve

Steve, probably less a classical RCM problem more a virtual RCM problem.
I don't think we can use this as an example of how classical RCM doesn't work.

Mike.

Sorry Mike... there was a pun intended - not a slur on RCM. The point is though, that a lot of programs get going and then stop. This one has stalled.

I may have missed it, but i was waiting for effects to be defined/ described/ exampled before I contribute to that aspect.

Where are we up to Rogier? Who are we waiting on?

It seam’s we have to overcome a problem which occur in most projects.
Lack of involvement due to different reasons is slowing things down
So we can conclude this virtual study is no different than a live one

Although I am a little disappointed in the contribution of some forum members who volunteered as active RCM team members I still see light at the end of the tunnel

The solution could be:

- to realease any unwanted feeling
- to dive into the core of the problem(s)
- do a powertalk,
- have a motivation campaign
- do a (virtual) teambuilding session and end with a nice dinner and free drinks

We are the team:

Rogier de Mulder
Steve Turner
Youssef X Abbaoui
Johnny W Campbell
Laurence Johnson
Bruno S Santos
Steven van Els
Trevor Sullivan
Mike W Ward

I will switch from facilitator to active working team leader and do an update before end of the week.

Let’s get back on track and finish what we started.
Give feedback
Be the first to finish a virtual RCM study ever!
Learn a lot
Be proud
Have a fun

I don't see the reason to bash the exercise or to compare it to a work effort. hummm,
I have either been lucky, or just determined. Typically projects I involve myself in have sponsorship/ priority/ champion commitment and rarely stall if delay at all. Seems you have had some leadership or failure to "sell" issues in the past. I have found taking personal ownership makes all the difference in the world.
The delay with this exercise was actually expected based on the forum, distance/ time zones, time of year (most Americans will be on vacation for the next 10 days and the past 2 weeks have been very busy at home and at work.) and the fact that this is a "hobby" exercise not a job.
I expect it running again by mid Jan. I personally will likely bow out till then as of this week.


Merry Christmas/ Holidays and New Year to all.

Hi All. New to this forum, but would like to join in on this thread. What can I do to help this project along?

Welcome to the effort.
Can you give us a little background on your knowlage of RCM or the relivent piece of equipment?