How Companies Can Manage Spreadsheet Risk [Part 2 of 4]

Share

Facebook
Twitter
LinkedIn

This series of articles will give you an overview of how to manage spreadsheet risk. These articles are written by Myles Arnott from Excel Audit

Introduction to Spreadsheet Risk Management

In the first article in this series we highlighted the risks that poorly managed spreadsheet solutions can introduce to a business. In this article we will demonstrate how companies can manage this risk.

A formal governance framework

The first, and arguably most important step is to ensure that the senior management team buy into the need for a robust spreadsheet risk management framework, and that they define and effectively communicate their spreadsheet risk management policy.

Spreadsheets identified and catalogued

It is impossible to know the level of spreadsheet risk in an organization without first identifying and then risk assessing all of the spreadsheets. It is therefore necessary to create a catalog of all of the spreadsheets and then to gather the key information about each spreadsheet to enable a risk assessment to be carried out.

The two key factors for determining the spreadsheet risk are the probability of there being an error and the impact that that error could have.

Risk = Probability of an error  X  impact if an error were to occur

The probability of error is related to the complexity of the spreadsheet. Complexity attributes differ across companies but include:

  • Spreadsheet size (Mbs)
  • Spreadsheet design (hard coded numbers in formulae, poor model structuring etc)
  • The number of users
  • The use of complex formulae (particularly array formulae, nested formulae etc)
  • The number of cells populated
  • The number of internal and external links
  • The use of VBA

The impact of the error is related to how critical the spreadsheet is within the business. Each company will have a slightly different definition of the impact levels of spreadsheets, but generally:

  • A spreadsheet is low impact if it is not used as part of a critical business process and an error would not have a material impact on the business.
  • A spreadsheet is medium impact if it contains confidential information and an error could have a material impact on the business.
  • A spreadsheet is high impact if it contains highly confidential information and an error would have a significant impact on the business. Spreadsheets used within processes that fall under external regulation (such as Sarbanes-Oxley and Solvency II) are deemed to be of high impact.

Finally, the spreadsheets should be placed in order of risk. Those identified as business critical and high risk should be prioritized for detailed review and placed under control.

This is clearly an on-going process. As new spreadsheets are developed they will need to pass through the risk assessment process as defined by the company’s spreadsheet risk management policy. A periodic review should also be carried out to ensure that all spreadsheets have been correctly categorized.

A best practice standard

The company should define its own best practice spreadsheet development standard that is applied to spreadsheets deemed to be medium or high impact. The standard should clearly outline the standards and conventions to which a spreadsheet should be built. New developments can then be reviewed to ensure that they adhere to the standard.

We advocate the use of the Excel Best Practice Standard from the Spreadsheet Standards Review Board (‘SSRB’).

We also recommend that tailored schedules are added to the standard to reflect your specific design standards. For example this could be a specific color scheme, use of logo or the use of specific text within the header or footer (e.g. document security levels).

Testing

A fundamental, but often overlooked step in the Excel model development cycle is testing. All spreadsheets (but especially business critical spreadsheets) need to be first peer reviewed and then rigorously tested.

It helps to consider the steps that an IT department would take to ensure that something they deliver is correct. It will pass through stages of unit and system testing prior to quality assurance and finally user acceptance testing. So why should a spreadsheet being used for a critical process be any different?

The fact is that no matter how hard we try, humans make errors. The purpose of testing is to identify them and get them resolved before the model goes into the live environment.

Remember that in the first article we highlighted the fact that 94% of spreadsheets and 5% of all formulae within spreadsheets contain errors.

Here is Scott Adams’ view on spreadsheet testing in Dilbert

 

 

Training

All staff should be trained so that they have sufficient Excel knowledge for their role and to use the spreadsheets that they are responsible for. As part of the induction process all staff should also be taught the company’s best practice standard.

Whilst this sounds obvious, research has shown that few companies prioritize investment in spreadsheet training.

 

Documentation

A key risk with spreadsheets is that they are often built and used by one individual within a team (often referred to as a “key man dependency”). If this person is ill or leaves unexpectedly the other members are totally reliant on the documentation left behind. From experience this rarely exists.

Each spreadsheet that is used within a process should as a bare minimum have documentation stating:

  • the purpose of the spreadsheet;
  • how the spreadsheet fits within the process;
  • the source of all inputs for the spreadsheet;
  • all key assumptions and drivers;
  • key calculations;
  • distribution list for outputs.

Spreadsheets that are part of as critical business process should have detailed documentation. This should include a technical specification and user notes.

 

Security

All business critical and confidential spreadsheets should be subject to access control. Security controls can be implemented across three levels:

  • Directory level: Only specific individuals have access to key directories
  • File level: Confidential and critical spreadsheets should be password protected to restrict access
  • Cell level: Non-input cells should be password protected

 

Change control, backups and archives

To minimize the risk of losing the current version of a spreadsheet and ensuring that the correct version is being used at all times, all business critical spreadsheets should be backed up, archived and subject to change control procedures.


So, in summary..,

the characteristics of a well-managed environment are:

  • a formal governance framework, sponsored by the senior management team, is in place for all spreadsheet development;
  • a catalog of spreadsheets is maintained and prioritized by risk profile;
  • a best practice standard is applied to the development of all new spreadsheets;
  • all new spreadsheets pass through a formal risk assessment, are peer reviewed and formally tested;
  • staff are provided with sufficient training to carry out their roles;
  • all spreadsheets and their associated processes are well documented;
  • access to critical spreadsheets is subject to security controls;
  • spreadsheets are subject to change control and are regularly backed up and archived.

What next?

In the next article we will look at the built in Excel functions that can help you to manage spreadsheet risk.

What about you?

How do you (or your company) manage spreadsheet risk? What best practices & guidelines you follow? Please share using comments.

Thank you Myles

Many thanks to Myles for writing this series. Your experience in this area is invaluable. If you enjoy this series, drop a note of thanks to Myles thru comments. You can also reach him at Excel Audit or his linkedin profile.

Facebook
Twitter
LinkedIn

Share this tip with your colleagues

Excel and Power BI tips - Chandoo.org Newsletter

Get FREE Excel + Power BI Tips

Simple, fun and useful emails, once per week.

Learn & be awesome.

Welcome to Chandoo.org

Thank you so much for visiting. My aim is to make you awesome in Excel & Power BI. I do this by sharing videos, tips, examples and downloads on this website. There are more than 1,000 pages with all things Excel, Power BI, Dashboards & VBA here. Go ahead and spend few minutes to be AWESOME.

Read my storyFREE Excel tips book

Overall I learned a lot and I thought you did a great job of explaining how to do things. This will definitely elevate my reporting in the future.
Rebekah S
Reporting Analyst
Excel formula list - 100+ examples and howto guide for you

From simple to complex, there is a formula for every occasion. Check out the list now.

Calendars, invoices, trackers and much more. All free, fun and fantastic.

Advanced Pivot Table tricks

Power Query, Data model, DAX, Filters, Slicers, Conditional formats and beautiful charts. It's all here.

Still on fence about Power BI? In this getting started guide, learn what is Power BI, how to get it and how to create your first report from scratch.

13 Responses to “Using pivot tables to find out non performing customers”

  1. David Onder says:

    To avoid the helper column and the macro, I would transpose the data into the format shown above (Name, Year, Sales).  Now I can show more than one year, I can summarize - I can do many more things with it.  ASAP Utilities (http://www.asap-utilities.com) has a new experimental feature that can easily transpose the table into the correct format.  Much easier in my opinion.

    David 

    • Chandoo says:

      Of course with alternative data structure, we can easily setup a slicer based solution so that everything works like clockwork with even less work.

  2. Martin says:

    David, I was just about to post the same!
    In Contextures site, I remember there's a post on how to do that. Clearly, the way data is layed out on the very beginning is critical to get the best results, and even you may thinkg the original layout is the best way, it is clearly not. And that kind of mistakes are the ones I love ! because it teaches and trains you to avoid them, and how to think on the data structure the next time.
     
    Eventually, you get to that place when you "see" the structure on the moment the client tells you the request, and then, you realized you had an ephiphany, that glorious moment when data is no longer a mistery to you!!!
     
    Rgds,

  3. JMarc says:

    Chandoo,
    If the goal is to see the list of customers who have not business from yearX, I would change the helper column formula to :  =IF(selYear="all",sum(C4:M4),sum(offset(C4:M4,,selyear-2002,1,columns(C4:M4)-selyear+2002)))
     This formula will sum the sales from Selected Year to 2012.

    JMarc

  4. Elias says:

    If you are already using a helper column and the combox box runs a macro after it changes, why not just adjust the macro and filter the source data?
     
    Regards

  5. RichW says:

    I gotta say, it seems like you are giving 10 answers to 10 questions when your client REALLY wants to know is: "What is the last year "this" customer row had a non-zero Sales QTY?... You're missing the forest for the trees...
    Change the helper column to:
    =IFERROR(INDEX(tblSales[[#Headers],[Customer name]:[Sales 2012]],0,MATCH(9.99999999999999E+307,tblSales[[#This Row],[Customer name]:[Sales 2012]],1)),"NO SALES")
    And yes, since I'm matching off of them for value, I would change the headers to straight "2002" instead of "Sales 2002" but you sort the table on the helper column and then and there you can answer all of your questions.

  6. Kevin says:

    Hi thanks for this. Just can't figure out how you get the combo box to control the pivot table. Can you please advise?
     
    Cheers

  7. Kevin says:

    Thanks Chandoo. But I know how to insert a combobox, I was more referring to how does in control the year in the pivot table? Or is this obvious?  I note that if I select the Selected Year from the PivotTable Field List it says "the field has no itens" whereas this would normally allow you to change the year??
     
    Thanks again

  8. Kevin says:

     
    worked it out thanks...
    when =data!Q2 changes it changes the value in column N:N and then when you do a refreshall the pivottable vlaues get updated 
     
    Still not sure why PivotTable Field List says “the field has no itens"?? I created my own pivot table and could not repeat that.

  9. Bermir says:

    Hi, I put the sales data in range(F5:P19) and added a column D with the title 'Last sales in year'. After that, in column D for each customer, the simple formula

    =2000+MATCH(1000000,E5:P5)

    will provide the last year in which that particular customer had any sales, which can than easily be managed by autofilter.

    • Bermir says:

      Somewhat longer but perhaps a bit more solid (with the column titles in row 4):

      =RIGHT(INDEX($F$4:$P$19,1,MATCH(1000000,F5:P5)),4)

Leave a Reply