What Is the Best Baselining Technique You Have Used?

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    Rhea Estrael

    Processes in the service industry changes drastically, thus the need to always create baseline targets.

    What are the statistical tools that you use to create baseline? How far back on the historical data that you would recommend using and by what frequency? (day wise, weekly, monthly)


    Robert Butler

    I’m not sure I understand what you mean by “statistical tools to create a baseline.”  Baseline data is just that – data gathered from a process before you attempt to make changes.  As for the data gathering itself – that is an entirely different matter.

    1. How often – I’ll take everything I can get with as much detail as I can get. This means if it is hourly – I’ll take hourly, if the best anyone can do is daily – I’ll take that.  The thing to remember is this – you can always take whatever data you may have and make it coarser but you can’t do the reverse.  In other words, it is easy to convert hourly into daily or weekly or whatever but you can’t go the other way. To put it another way – if you are given continuous data in any form – keep it – do not record the data as binned data – after you have entered the data you can have the computer bin the data any way you want.

    2. How far back in time – that will depend on a number of things and you will have to get the answers to those questions before you start gathering the data.

    a. Are the measurements for whatever it is that you are measuring the same across time?  If not then there will be a time horizon beyond which it won’t make much sense to gather additional information. For example, for the last two years you have been taking measurements in millimeters/second, however, prior to that you were taking measurements in furlongs/fortnight. In this case your data horizon is two years.

    b. Have there been any major changes to the way the process was run? Changes in measurement methods, switches in sources of major raw material suppliers, major changes/upgrades in machinery used in production, major changes in operation protocol, etc.

    For example, up until last year we ran the process by looking at the settings of three gauges twice a day and made adjustments based on those readings. A year ago we went to hourly readings and adjustments and six months ago we went to automated continuous feedback.  The time horizon is now 6 months.

    Consequently, If you have a situation where both a and b are true then there’s no point in going back any further than 6 months.

    There are other issues but, in my experience, these are the big ones.


    Chris Seider

    Yes, your service industry definitely has many peaks and valleys–especially if in the retail arena.

    Some thoughts to consider

    1.  How “easy” is past data for the metric that was agreed by the project sponsor/project leader?  If easy, see if any sign of seasonality and that may help you decide on what time frame for getting an average or standard deviation–depending on project scope.

    2.  If the data isn’t easy to get, then maybe one should challenge how one knows there is a problem and then track that “pain point” also which should easily be made available.

    3.  Don’t spend too much time on creating a baseline chart and “dig in”.


    Mike Carnell

    @rheaestrael Probably not much different answer than @Robert Butler or @cseider. You take everything you can get as far back as you can get it and plot it. No nonsense control chart stuff just a plain time series plot and look at it for patterns, trends, runs, shifts and cycles. Then you mark the things Robert suggested where the process has changed and where the data has changed and look at the effect.

    That is all Baseline data. No you need to make an informed decision on what baseline data is relevant to what you are dealing with today.

    I don’t know what this comment means “Processes in the service industry changes drastically,….” but I would figure out why it changes drastically and if it makes sense that it changes drastically. If you rational for the changes has these words in it “we are different….” then you are mistaken and you need to rethink it.

    Just my opinion

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