Why Spreadsheet Dependency Analysis Matters Before ERP Migration

A spreadsheet can appear simple on the surface while relying on a network of formulas, worksheets, reference fields and outputs underneath.

During ERP, CRM or application transformation, those dependencies matter because changing or rebuilding one part of the process can affect several others.

If those relationships are not understood during discovery, migration teams can preserve the visible data while accidentally losing the logic that connects it.

Understanding a workbook means understanding not only what it contains, but what depends on what.

What is a spreadsheet dependency?

A spreadsheet dependency exists when one field, formula, worksheet or output relies on another.

Dependencies may exist between:

• cells
• fields
• tables
• worksheets
• calculations
• reference data
• business outputs

For example, a management dashboard may appear to contain only a few outputs while those outputs depend on calculations spread across several other sheets.

The dashboard may be the visible result, but the business logic exists across the entire chain.

Why dependencies are important during ERP migration

One change can affect several outputs

A small formula or field change can influence calculations elsewhere in the workbook. If a migration team only reviews the changed cell, it may miss the downstream effect.

Dependencies can represent undocumented requirements

Cross-sheet relationships often reveal how the business process actually works.

For example, a pricing output may depend on:

• customer classification
• product cost
• discount rules
• manual adjustments
• tax or fee calculations

Those relationships may never have been written down as formal requirements.

Important source data may live outside the visible output

A user may only care about the final total, but the calculation may rely on inputs controlled by different teams or stored on different sheets.

During migration, the project team needs to understand which source fields must move and where their future source of truth will be.

Dependencies can affect UAT

If an output depends on several upstream calculations, testing only the final output may not be enough.

UAT may need to validate the important dependency chain as well as the result.

Cross-sheet dependencies can be easy to miss manually

Complex workbooks often contain formulas that reference fields from other worksheets.

When this happens repeatedly, the workbook effectively forms a dependency network.

Reviewing that network manually can become difficult when a workbook contains hundreds of formulas.

One IC-Flow demonstration workbook contains:

This is exactly the type of workbook where high-level inspection can miss how calculations and outputs depend on one another.

From formula dependency to business impact

Dependency analysis becomes more useful when the technical relationship is translated into business context.

This creates a much clearer bridge between spreadsheet logic and target-system requirements.

Types of spreadsheet dependencies to review

Formula dependencies

One calculation relies on another field or formula.

Cross-sheet dependencies

A formula references values from another worksheet.

Reference-data dependencies

Calculations rely on lookup tables, classifications or master data.

Output dependencies

A business-facing output depends on one or more upstream calculations.

Manual dependencies

A process depends on a person entering or adjusting a value manually.

Process dependencies

One sheet may only be updated after another operational step has taken place.

Why dependency depth matters

Not all dependencies have the same importance.

A direct reference between two fields is different from a deep calculation chain where an important output depends on several upstream formulas.

The deeper the chain, the easier it can be for a change to have an unintended effect.

For migration planning, deeper chains may deserve additional review, especially where the final output influences finance, pricing, customer decisions or operational activity.

Dependencies can reveal hidden migration scope

A project may initially assume that only one spreadsheet or one worksheet needs to be replaced.

Dependency analysis can reveal that the process actually relies on:

• multiple worksheets
• multiple input sources
• reference tables
• manual adjustments
• linked outputs
• repeated calculations

This can change the understanding of what the target system needs to support.

Dependency analysis can support target-system design

Once important dependencies are identified, the implementation team can decide where the logic should live in the future system.

For example:

• a lookup may become master data
• a formula may become a calculated field
• a manual step may become a workflow
• a dashboard output may become a report or KPI
• a cross-sheet relationship may become a database relationship

The spreadsheet dependency itself does not dictate the target design. It provides evidence that the underlying relationship needs to be considered.

Dependency analysis can improve requirements discovery

A useful discovery discussion might move from:

What columns are in this workbook?

to:

Which calculations depend on these fields?
Which outputs depend on those calculations?
Who relies on those outputs?
What must happen in the target system instead?

That is a more useful requirements conversation.

Dependency analysis can support change review

Dependencies are also important when workbook versions change.

If a formula is modified, the next question should be:

What does this changed formula affect?

The strongest change-review workflow is:

This helps move version comparison beyond a simple technical diff.

Questions to ask about spreadsheet dependencies before migration

1. Which worksheets depend on other worksheets?
2. Which formulas feed important business outputs?
3. Which fields act as upstream inputs?
4. Which reference tables or lookup sources are critical?
5. Which dependencies cross business processes or teams?
6. Which outputs have deep calculation chains?
7. Which dependencies rely on manual adjustments?
8. Which relationships need to exist in the target system?
9. Which dependencies should be tested during UAT?
10. Who can confirm that the detected relationship still reflects the current process?

How IC-Flow supports spreadsheet dependency analysis

IC-Flow is designed to help analyse spreadsheet logic before ERP, CRM or application transformation.

Its workbook analysis can help identify:

• formula relationships
• cross-sheet references
• key inputs
• important outputs
• dependency graph relationships
• business rules linked to spreadsheet logic
• migration-readiness considerations
• review and sign-off questions
• suggested validation tests
• target-system planning guidance

These findings can then form part of the Migration Readiness Assessment and Evidence Pack used during discovery, review, UAT planning and handover.

Dependency analysis is about understanding impact

The value of dependency analysis is not simply seeing arrows between spreadsheet cells.

The useful question is:

If this input, formula or worksheet changes, what else might be affected?

That question is important before migration because the target system needs to preserve the business behaviour that still matters, not merely copy the structure of the workbook.

Before migrating the spreadsheet, understand what depends on it

What does this workbook do?
What depends on it?
What changed?
What must be preserved?

IC-Flow helps turn those questions into structured migration evidence.