Spreadsheets have a notoriously high number of faults.
Rust, et al (2006)
A significant proportion of spreadsheets have severe quality problems.
Ayalew (2007)
Spreadsheets are dangerous to their authors and others.
Durusau & Hunting (2015)
1% of all formulas in operational spreadsheets are in error.
Powell, Baker, & Lawson (2009)
Most executives do not really check or verify the accuracy or validity of [their] spreadsheets...
Teo & Tan (1999)
People tend to believe their spreadsheets are more accurate than they really are.
Caulkins, Morrison, & Weidemann (2006)
Your spreadsheets may be disasters in the making.
Caulkins, Morrison, & Weidemann (2006)
Most large spreadsheets have dozens or even hundreds of errors.
Panko & Ordway (2005)
Overconfidence is one of the most substantial causes of spreadsheet errors.
Sakal, et al (2015)
Studies have shown that there is a high incidence of errors in spreadsheets.
Csernoch & Biro (2013)
A lot of decisions are being made on the basis of some bad numbers.
Ross (1996)
The quality and reliability of spreadsheets is known to be poor.
Bishop & McDaid (2007)
Spreadsheets are alarmingly error-prone to write.
Paine (2001)
Never assume a spreadsheet is right, even your own.
Raffensperger (2001)
It is now widely accepted that errors in spreadsheets are both common and potentially dangerous.
Nixon & O'Hara (2010)
It is irrational to expect large error-free spreadsheets.
Panko (2013)
The issue is not whether there is an error but how many errors there are and how serious they are.
Panko (2007)
Errors in spreadsheets are as ubiquitous as spreadsheets themselves.
Colbenz (2005)
60% of large companies feel 'Spreadsheet Hell' describes their reliance on spreadsheets.
Murphy (2007)
94% of the 88 spreadsheets audited in 7 studies have contained errors.
Panko (2008)
Spreadsheets are extraordinarily and unacceptably prone to error.
Dunn (2010)
Despite being staggeringly error prone, spreadsheets are a highly flexible programming environment.
Abreu, et al (2015)
Spreadsheet development must embrace extensive testing in order to be taken seriously as a profession.
Bock (2016)
Spreadsheet errors have resulted in huge financial losses.
Abraham & Erwig (2007)
Even obvious, elementary errors in very simple, clearly documented spreadsheets are... difficult to find.
Galletta, et al (1993)
Spreadsheets can be viewed as a highly flexible programming environment for end users.
Abreu, et al (2015)
The software that end users are creating... is riddled with errors.
Burnett & Myers (2014)
Spreadsheets are the most popular live programming environments, but they are also notoriously fault-prone.
Hermans & van der Storm (2015)
Spreadsheets contain errors at an alarmingly high rate.
Abraham, et al (2005)
Research on spreadsheet errors is substantial, compelling, and unanimous.
Panko (2015)
Untested spreadsheets are riddled with errors.
Miller (2005)
Errors in spreadsheets... result in incorrect decisions being made and significant losses incurred.
Beaman, et al (2005)
Developing an error-free spreadsheet has been a problem since the beginning of end-user computing.
Mireault (2015)
Despite overwhelming and unanimous evidence... companies have continued to ignore spreadsheet error risks.
Panko (2014)
Spreadsheet errors... a great, often unrecognised, risk to corporate decision making & financial integrity.
Chadwick (2002)
Spreadsheets are easy to use and very hard to check.
Chen & Chan (2000)
Spreadsheet shortcomings can significantly hamper an organization's business operation.
Reschenhofer & Matthes (2015)
Spreadsheets are more fault-prone than other software.
Kulesz & Ostberg (2013)
Programmers exhibit unwarranted confidence in the correctness of their spreadsheets.
Krishna, et al (2001)
Spreadsheets are notoriously error-prone.
Cunha, et al (2011)
The results given by spreadsheets are often just wrong.
Sajaniemi (1998)
Spreadsheet errors are pervasive, stubborn, ubiquitous and complex.
Irons (2003)
Spreadsheets... pose a greater threat to your business than almost anything you can imagine.
Howard (2005)
Every study that has looked for errors has found them... in considerable abundance.
Panko & Halverson (1996)
Spreadsheet errors are still the rule rather than the exception.
Nixon & O'Hara (2010)
The untested spreadsheet is as dangerous and untrustworthy as an untested program.
Price (2006)
...few incidents of spreadsheet errors are made public and these are usually not revealed by choice.
Kruck & Sheetz (2001)
Every study, without exception, has found error rates much higher than organizations would wish to tolerate.
Panko (1999)
Spreadsheets are often hard, if not impossible, to understand.
Mireault & Gresham (2015)
Spreadsheets are commonly used and commonly flawed.
Caulkins, Morrison, & Weidemann (2008)


Connexion is a collection of the most useful and interesting spreadsheet-related articles from the web.

We review more than 200 websites and blogs to collect the best articles on tools, tips, and techniques that help you to improve your spreadsheets. Each article here is just a snippet — click on the title to open the full article.

Number of Connexion articles: 284

10 reasons for Excel formulas not working (and how to fix them)

10 reasons for Excel formulas not working (and how to fix them)

21 May 2021

"Oh My God" Excel formulas not working in my report. Sounds familiar right? If so, don't worry, you are just one among many Excel users who face this problem very often.

To avoid all this hassle, we have written this in-depth article covering most of the reasons for Excel formulas not working. And how to fix them.

10 reasons for Excel errors:

  • Calculation options.
  • Excel formula not calculating, just showing formula.
  • Extra space(s) is an extra headache.
  • Get rid of nonprintable/hidden characters.
  • Excel formatting – don't try to compare apples with oranges.
  • Circular references.
  • Using double quotes incorrectly.
  • BODMAS - basic rule for every calculation.
  • Incorrect use of "absolute" referencing.
  • Incorrect formula arguments.
Optimization models in Excel

Optimization models in Excel

26 February 2021

Solver Max, a sister company of i, provides a collection of optimization model examples using the Solver and OpenSolver add-ins.

Models include:

  • Facility location. Where should we locate our facility to maximize profit?
  • Job sequencing. What is the best sequence for the jobs that we need to complete?
  • Wire cutting. What is the best way to cut our stock material to minimize waste?
  • Fantasy sports. How can we select an optimal team for a fantasy sports competition?
  • Production mix. What mix of products should we make to maximize profit?
Excel: Why using Microsoft's tool caused Covid-19 results to be lost

Excel: Why using Microsoft's tool caused Covid-19 results to be lost

8 October 2020

The BBC reports that a "badly thought-out use of Microsoft's Excel software was the reason nearly 16,000 coronavirus cases went unreported in England."

Although Excel has been the target of much blame, and even contempt, the issue is much deeper than that.

As two authors from the Institute of Chartered Accountants in England and Wales (ICAEW) point out, the issue isn't Excel as such, but rather the way that we use Excel:

Excel formulas not working: Possible reasons and how to fix it!

Excel formulas not working: Possible reasons and how to fix it!

26 July 2020

If you work with formulas in Excel, sooner or later you will encounter the problem where Excel formulas don't work at all (or give the wrong result).

In this article, I will highlight those common issues that are likely the cause of your Excel formulas not working.

This tutorial covers:

  • Incorrect syntax of the function.
  • Extra spaces causing unexpected results.
  • Using manual calculation instead of automatic.
  • Deleting rows/column/cells leading to #REF! error.
  • Incorrect placement of parenthesis (BODMAS).
  • Incorrect use of absolute/relative cell references.
  • Incorrect reference to sheet / workbook names.
  • Circular references.
  • Cells formatted as text.
  • Text automatically getting converted into dates.
  • Hidden rows/columns can give unexpected results.
Why implementing a financial modelling standard is hard

Why implementing a financial modelling standard is hard

16 February 2020

Modelers across the globe are beginning to recognise financial modeling as a profession.

Despite strong support for professional standards many modeling teams do not implement them rigorously and a suprising number of teams do not have consistent quality control systems in place.

Key conclusions from "2019 Financial Modeling Profession Survey":

  • 84% of modelers agree that financial modeling is a dynamic and innovative profession.
  • Errors in models remain common. 47% of respondents reported errors that were not picked up by internal review processes.
  • Most financial modelers are self-trained and rarely attend formal financial modeling training courses.
The VLOOKUP slayer: XLOOKUP debuts Excel

The VLOOKUP slayer: XLOOKUP debuts Excel

28 August 2019

Introducing XLOOKUP, a replacement for VLOOKUP and HLOOKUP.

The main benefits of XLOOKUP:

  • Can find the last match!
  • Can look to the left!
  • Defaults to an exact match (unlike VLOOKUP which defaults to True for the 4th argument).
  • Defaults to not support wildcards, but you can explicitly allow wildcards if you want them.
  • Has all the speed improvements released to VLOOKUP in 2018.
  • No longer relies on Column Number, so it won't break if someone inserts a column in the middle of the lookup table.
  • Performance improvement because you are only specifying two columns instead of the whole lookup table.
  • XLOOKUP returns a range instead of VLOOKUP returning a value.
Avoiding keyed in values in Excel formulas

Avoiding keyed in values in Excel formulas

5 June 2019

One of the cardinal rules of Excel is don't key-in a value into a formula if that value could change.

Tracking the value down could be problematic if you need to change the value. Tables can be the solution to avoiding keyed-in values.

Care with modifying numbers

Care with modifying numbers

26 May 2019

Often when building even a simple financial model, unit conversion is necessary.

For example, you sell 437,911 widgets at £12.50 each. However, in your output summary sheet for senior management, do you really wish to show that the revenue earned is £5,473,888 or is it more likely that you will display this figure as £5.5m?

Most modellers will modify their number with a calculation such as =437911*12.50/1000000. But using this approach poses the danger of making a mistake in your additions by adding £ and £millions.

By using a custom number format, rather than modifying values, you will never again add or subtract numbers of different orders of magnitude.

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