According to research by Ray Panko, of the University of Hawaii and others, 90% of spreadsheets contain at least one mistake. While a single error slipping through the net might not seem significant, allowing mistakes to regularly go unnoticed could prove incredibly costly.

In this article, we’ll explore the different stages of a spreadsheet review, examining why they’re so important for highlighting errors, and what you can do to streamline the process for optimal efficiency.

What is a Spreadsheet Review?

A spreadsheet review typically refers to the process of examining and evaluating a spreadsheet to ensure its accuracy, completeness, functionality, and adherence to relevant standards or requirements.

Why Do Spreadsheets Need Reviewing?

The purpose of a spreadsheet review is to identify and correct any errors, inconsistencies, or issues that could impact the accuracy or reliability of the spreadsheet’s data and calculations.

This helps to ensure that the spreadsheet can be used effectively for its intended purpose and that decisions based on its information are reliable.

Common Mistakes:

Before exploring the stages of a spreadsheet review, it’s important to first recognise some common errors that often go undetected:

• Formula errors – One of the most frequent mistakes found in spreadsheets, entering incorrect formulas can lead to inaccurate calculations.
• Manual errors – Manual entry mistakes such as typos might seem minor, however, they can compromise the accuracy of the entire spreadsheet.
• Missing information – Forgetting to input data in certain cells or rows can impact analysis and cal=culations, particularly if formulas depend on that missing data.

The Stages of a Spreadsheet Review

Initial Review

Before data input begins, conducting an initial review is crucial. Key questions to address include:

• What is the Purpose of the Spreadsheet?
  Take the time to understand the key spreadsheet outputs that are being sought, including the decisions to be informed by these outputs and the stakeholders dependent on them.
• Is There a Level of Risk?
  Conduct a thorough risk analysis of the spreadsheet and ensure your review focuses on the calculations that underpin critical values.
• What is the Lifecycle of the Spreadsheet?
  A spreadsheet designed to support a single event will have a different structure to one with ongoing use.

By answering these questions in detail, you can gain a better understanding of the spreadsheet’s significance, tailoring the review process accordingly.

Structural Review

Once you’ve completed an initial review, you now need to assess the spreadsheet itself. The aim of a structural review is to provide an overview of the entire spreadsheet without getting into the finer details.

Some key considerations may include:

• Is the spreadsheet fit for purpose?
• Is there a clear structural overview?
• Is direction provided to all users?
• Is the layout consistent throughout?
• Are formulas overly complex?
• What time period are calculations based on? Are they consistent?
• Does the spreadsheet have clear and consistent formatting?

In a large spreadsheet with numerous cells and formulas to evaluate, conducting an accurate manual review can feel like an impossible task – that’s where a spreadsheet review software comes in.

With Operis Analysis Kit’s (OAK) Summarize tool, you can quickly and easily review and interpret a model, providing a general understanding of the reasoning behind the spreadsheet’s layout, structure and formulas.

Data Review

A swift yet crucial stage, data review involves verifying the accuracy of data inputs and testing for any glaring flaws that could compromise accuracy.

Analytical Review

A separate analysis of spreadsheet outputs is essential to ensure accuracy.

Ask yourself:

• Do the assumptions and results look reasonable?
• Can charts aid in pinpointing areas requiring further scrutiny?

During an analytical review, the use of charts can be extremely helpful, pointing to places inside the spreadsheet that may require additional research.

Detailed Review

Designed to validate the details within the spreadsheet, the steps performed at this stage in the process will be unique to the context, scale and risk of the spreadsheet being reviewed.

Your review may include:

• Inspecting the workbook
• An independent analysis
• Testing formulas
• Installing a software diagnostic tool

Programmed to search for problems and generate findings, integrating OAK into your workbook accelerates the spreadsheet review process.

The ‘Formula Walker’ tool serves as the ideal solution for formula verification, streamlining formula auditing and navigation.

Post-Review | What Happens Next?

Upon completing a spreadsheet review, it’s important to document your findings and communicate them to relevant stakeholders. It’s crucial to record what checks have been carried out, and what type of testing, if any, has been conducted.

This should be completed on a separate worksheet within the workbook that was under review. A copy of the review sheet should be archived, and any amendments should undergo further review.

Want to Improve Your Spreadsheet Review Process? Choose OAK

OAK can save you valuable time and effort throughout every stage of a spreadsheet review, assisting you in checking for errors, streamlining feedback, verifying outputs and so much more.

Start a 30 day free trial today!

Our knowledgeable team is always on hand to help, offering specialist advice and support throughout your trial period and beyond. Call us today on +44 (0)20 7562 0400 or fill in our enquiry form and we will get back to you soon.