Performance based maintenance plan scheduling

[#1]

Dear PM Gurus,

I have a performance based plan, where my counter is recording running hours of a machine. Here are the details of the counter and maintenance plan:

Annual Estimate of counter: 1200 hr

Cycle length of maintenance plan: 10 hr

Call horizon: 100%

First measurement document: 9 hr

Start of cycle: 0 hr

As per my understanding, if I schedule this plan the first call should be 'On Hold', since counter reading (9 hr) has not yet reached the cycle length (10 hr). But currently I am getting the first call as 'New Start, Save to call'.

Any idea why system is behaving in this way?

Regards,

Nihal N.

[nihal_nayak · Accepted solution]

So after I posted this question, I did some more testing and have concluded the following:

1. As my annual estimate is 1200 hr, the activity per day = 1200/365 = 3.28 hr / day.

2. System determines the planned maintenance date by calculating the date whenever 10 hours (cycle length) would ideally be completed. Since my current reading is 9 hr (which I entered in system today), the planned date would be whenever the remaining 1 running hours (10-9) are completed. As each day the machine runs for 3.28 hours, system assumes that the 1 hour has been/will be completed today. That's why it generated a call at 9 hr counter reading (i.e, on today's date).

To put this into a formula:

Next planned date: Date on which current reading was entered + Offset.

Offset = (Cycle Length reading - Current Reading) / (Activity per day)

Note:

a) If current reading is larger than cycle length, then need to take the next multiple of cycle length.

b) Offset is always a whole number, so SAP rounds off the value calculated in the above formula to the closest whole number.

I tested this using different annual estimates and cycle lengths, with results consistent with the above explanation. What I have realized is not to look at the counter readings in isolation, rather, we also need consider the difference between current reading and cycle length, and date on which the current reading has been entered in SAP.

Nihal.

[peter_atkin]

You are correct..

The usage of the equipment will vary due many reasons e.g. operational changes, dual redundancy, etc.

So one VERY important factor you need to consider with performance-based maintenance plans is the periodic review of the Annual Estimate values.

PeteA

[peter_atkin]

Nihal N

Can you please post scree-shots of the following:

• The IP10 calls
• The IP03 schedlling parameters

Also, 9Hr is an actual measurement reading from which the plan calculates the next calls.

PeteA