11 
  
interest 
rate ; 
0% 5% 6% 8% 10% 12% 15 % 
period 
  
  
  
3 years 33.3 36.7 37.4 38.8 40.2 41.6 43.8 
  
4 years 25.0 28.2 28.9 30.2 31.5 32.9 35.0 
  
5 years 20.0 23.] 23.7 25.0 26.4 27.7 29.8 
6 years 16.7 19.7 20.3 21.6 23.0 24.3 26.4 
  
  
  
  
  
  
8 years 12.5 15.5 16.1 17.4 18.7 20.1 22.3 
10 years 10.0 13.0 13.6 14.9 16.3 17.7 19.9 
12 years 8.3 11:3 11.9 13.3 14.7 16.1 18.4 
15 years 6.7 9.6 10.3 117 13:1 14.7 17.1 
20 years 5.0 8.0 8.7 10.2 11.7 13.4 16.0 
  
  
  
  
  
  
  
  
  
  
  
figure 3 sample of annuity percentages 
Having established annual equipment costs, the next step is the 
derivation of the equipment cost standards per time unit. This requires that 
an estimate be made of the number of time units (hours or days) during which 
an item will be used per year, and as such will depend on factors such as the 
anticipated work load, the number of shifts worked per day, the number of 
staff using the item of equipment, etc. Attention should be paid to the fact 
that this estimate tends to trigger off a positive feedback. If the time estimate 
is too high, the corresponding cost standard will be lowered, resulting in a 
tendency to use that particular item of equipment more intensively. The 
reverse situation occurs when the time estimate is too low.