There is not such a thing as a unplanned failure

Special levies, deferred maintenance, repeat pattern breakages

Sounds familiar….the consequences

We will show you how to transform the unknown into an opportunity  in 4 steps.

Gate motors is often a headache due to its tendency to randomly break.

  • Scenario: Gate motor : Current replacement cost R6600 . Expected useful life 7 years, actual age 4 years. No specific maintenance cycle. 1 failure in past 3 years. How do you plan?
  • By doing a few calculations can we change the issue completely.EUL


Rather than be stuck with the unknown, how about this:

Using the method below gives you the following insight:

  • the probability of a failure this year is 75.4%. Risk provision R4950.
    • If your maintenance & repair cost for the year + Risk cost :
      • Exceed replacement cost —replace rather than to repair.
      • Less than the replacement cost —better to repair.
  •  If you implement a maintenance cycle the probability drops to 27% and risk provision to R1782. See how that change the situation : less provision required and extend the useful life of the item. The 20/80 principle.


If you are a property manager then you will agree that 80% of your time is spent on resolving unplanned failures and 20% on doing your actual job . Big picture perspective on this is that you are wasting at least  60%  of you time, your resources, funding on the wrong things…That could have been prevented or at least foreseen 80% of the time.

Unplanned failures are a product of planning, not an event.

There is proven methods to determine the probability of a failure and provision for the event in advance, with a high degree of accuracy.   These methods are typically used within the formulation of a LTMP. If you want to read more on LTMP click here. We will use those methods but in a more practical way here.

Here is the steps you follow to transform unplanned to planned events (failures)

Step1. Calculate the item’s effective condition age

Understand your structural item. It specifications, its life cycle and associated events. Give an age rating given its current condition.

  • Determine its expected useful life(EUL). Eg timber window 40 years
  • Will it’s still be in a functional working condition by the end of the year, if you do nothing and you don’t have factual information to indicates that it will fail in this year. So you expect it to last. Be realistic. If it looks old then it is, If it looks new, then it is. If it looks neglected..then it is.
  • Calculate its effective age
    • Old = 75% * EUL
    • New = 100% * EUL
    • Neglected = 50% * EUL

Step 2. Create a health index.

This matrix is a generic view(index)  of the factors that underpin the property. The Iso standard is the following variables: Item quality, design, Workforce, Internal and external environmental factors, usage and maintenance adherence .

  • Give each a rating (.8 for negative, 1 for neutral, 1.2 for positive)
  • Index ratio = product of rating

Step 3. Create a Density ratio.

This ratio is a factor of historical events.

  • 1.2 = more that 1 failure in the past 3 years
  • 1 =  at least 1 Failure in the past 3 years
  • 0.8 = Less 1 failure in the past 3 years

Step 4. Calculate the Failure probability

For this you will need  MS excel and the above calculations

Calculate the cumulative normal distribution.

  • x factor =  is your items actual age
  • Mean = Condition  EUL * Index ratio / density ratio
  • Distribution = Original EUL *25%

You failure probability % is the probability that you will have at least 1 breakage in the next year. More that 100 indicates more than 1 failure

That’s it. Now you must just use the information

Step 5. Create a plan for the failure

Consider pre-emptive measures to prevent the failure such as planned maintenance/renewal or replacement

  • If preventable consider consequence minimizing measures and provision for funding  ..See our publication on risk cost calculation
  • Risk cost provision is a discounted financial provision for a failure , irrespective of it happening or not.

Fact:  if you fail to plan  then … plan to fail.