1. Profile photo of utkurjon says


    I would like to thank you and Open Tuition for the great lectures which helps my studies to be a lot easier.
    However, I came to a question where I have a little problem. Would you be kind to help me how to deal with it please.

    The question is from ACCA Global and it is as follows:

    Example 2
    The first batch of a new product took six hours to make and the total time for the first 16 units was 42.8 hours, at which point the learning effect came to an end.

    Calculate the rate of learning.

    ACCA Global suggested using equation but not the learning curve formula.
    the final step to get the answer, it tells to take the fourth root of each side that involves using the calculator button r4 or calculator button x1/y to find the forth root of a number. However, both my calculators do not have these buttons and even looked my calculator guides but there is nothing mentioned about theses buttons.
    Could you suggest how to take the forth root or any alternative approach to the question.

    Many thanks in advance.

  2. Profile photo of Aley says

    Dear John,
    In example 6 by formula ,if we calculate total time of 8 units answer verify the doubling rule no need to find total time for 9 units and then subtract 1st unit time ,it means we can calculate total time for n units,But why it is not verifying answer for 7 units why we should find 8 then subtract first unit time.

    Prompt reply is highly appreciated.

    • Profile photo of John Moffat says

      Whether using the formula or using the doubling rule, you can only get the time for the first number to be made (i.e. you can calculate the time for the first 4, or the first 5 or the first 6 and so on). If you have made some units already, then you cannot work out directly the time for another 4, or another 5, or another 6 etc..
      The only way you can do it is the way in the lecture.

  3. avatar says

    Thanks John Moffat for the lecture, is well explained. However, I have one small problem, I wish to know the difference between total time for the next 7 and total time for 7. In example 6 you calculated total time for the next 7 and got 237.5 and I tried to calculate total time for 7 using the formular I got 312.22 . I was hoping to get 237.5. So i was wondering if they don’t mean thesame thing.

    • Profile photo of John Moffat says

      When it says the next 7 it means another 7 after the one already produced – so it bring the total up to 8.

      So to get the time for the next 7 you need to calculate the total time for 8 and then subtract the time it took for the first one.

      • avatar says

        Dear John,
        Thanks for the prompt reply to my question. It is now understood.Thanks once more for the excellent lectures you are giving in this site.

  4. avatar says

    In the last part of the question where the total time for the 30 batches was calculated, why was the average time of 90.80 multiplied by 30 to get 2,724?
    I thought the average time of 90.08 which was calculated for the 30 batches would have been used.

  5. avatar says

    Thank you for the useful lecture. I was just wondering if u can help me with working it out on the calculator as I can’t seem to find the symbol Xy and +/y to work out the answer for Example 7?

    Many Thanks

    • Profile photo of John Moffat says

      I can’t really help, because there are different types of calculator with different ‘logics’ which affects the order in which you press the keys.
      Sorry, but you are going to have to search in the manual that came with the calculator :-(

      • avatar says

        I thought you might say that :-( I have found how to do the Xy symbol but not the +/- but I’ll have a look at the manual again. Thanks again for the lecture!

  6. avatar says

    Hello Sir, thanks for the great work. I need a clarification. Why is it that when learning rate increases, average time also increases. I thought as learning rate increases which means people learn faster, then average time taken to produce the product should reduce. For example when first unit takes 200hrs and learning rate is 60% then average time is 120hrs for second unit, if the rate increases to 70%, the average time rather increases to 140hrs which confuses if compared to real life.

    • Profile photo of John Moffat says

      I realise that in other contexts we tend to think of it as the higher a percentage it then the better, but in the case of learning rates this is not the case.

      The lower the learning rate the faster they are learning. We would want the learning rate to be as low as possible. A learning rate of 70% is better than a learning rate of only 90% – the 70% people are learning faster.

      • avatar says

        Thanks for the quick response but still not very clear. What does the percentage really mean then? I take it as it means the rate at which the workers are learning and if so then the faster the better so the higher the rate the better. That’s why am thinking that way. Probably it means something different. I will be clear if u can help me with that thing.

      • Profile photo of John Moffat says

        Don’t look for a meaning! All it means is that the average time falls to that percentage of the previous average time.

        It is a measure for us to find how fast they are learning, but not in the way that you are trying to interpret it. Too many think that way without understanding how it is working (which is why the examiner once asked as a small part of a question – which is better, a learning rate of 80% or a leaning rate of 90%. The answer is 80%).

        (Higher percentages are not always better. If I told you that my company wastes 10% of my raw material and another company wastes 5% of its material, it certainly does not mean that my company is doing better :-) )

      • avatar says

        I got it. Thanks very much. It means For example, an 80 percent
        learning curve means the per unit average
        cumulative cost (in hours or dollars) falls to 80
        percent of the previous per unit average
        cumulative cost as the cumulative output
        doubles. Therefore the lower it falls the better.

        Thanks very much for your reply.

    • Profile photo of John Moffat says

      As is made very clear in the introduction paragraph to the Course Notes, you will not be asked for calculations on regression or on time series. (The calculations are examined in Paper F2)

      You are only expected to know the principles. I have only left the calculations in the notes (and lectures) to hopefully make the idea more clear.

    • Profile photo of John Moffat says

      Time series and regression analysis are assumed knowledge from Paper F2. The examiner has said that there will not be detailed calculations on either, but you are expected to be aware of both.
      (If you look at the course notes, it actually says this in bold letters. We update our notes every six months and everything in our notes is relevant for the December 2013 exams)

    • Profile photo of John Moffat says

      Time series are unlikely to be asked, but they are assumed knowledge from Paper F2. You will certainly not be asked for calculations, but you can be expected to know what time series are.

  7. avatar says

    Urgent help plzzz tomorrow i have my F5 paper …
    In learning curve the formula method how do find values of the logs ??
    will i be given log table ??? or should i carry my own ?? or am i allowed to use scientific calculator ?

    • Profile photo of John Moffat says

      @safwandeshmukh, You are not given log tables and you cannot take your own. But you are allowed to use a scientific calculator.

      However, almost certainly you will be given the value of b if learning curves are asked.
      (but you will still need a scientific calculator to calculate y = ax^b )

  8. avatar says

    I am working Question 3 on Past Paper Dec 2008. When I calculate the time it takes to fit 199 kitchens using the method provided by OpenTuition, I am arriving at a different answer from the examiner. Could anyone shed some light on this?

  9. avatar says

    Awesome lecture….the only problem i’m facing is once the lecture is almost in it’s last part, it gets back to the beginning!!!
    Reached the part where the lecturer was teaching how to calcuate “LOG R” and then the video gets back to beginning….What’s that suppose to be???Any idea!!!

Leave a Reply