Spreadsheet-Based Planning

What is spreadsheet-based planning?

Spreadsheet-based planning is the merchandising planning model in which OTB financial plans, assortment architectures, buy plans, allocation schedules, and in-season analytics are created and maintained in separate Excel or Google Sheets files — typically owned by different team members, stored in different folders, and connected only through manual copy-paste or email-based handoffs. Despite the availability of purpose-built planning platforms, spreadsheet-based planning remains the dominant approach for mid-market apparel brands with $20M-$200M in revenue.

Spreadsheets are flexible, familiar, and free. They are also disconnected, error-prone, and invisible — and the planning failures they produce are expensive.

Why spreadsheet-based planning matters in apparel

Understanding spreadsheet-based planning matters because it is the system most apparel brands are actually using — and its limitations directly cause the margin erosion, missed opportunities, and planning delays that merchandising teams experience every season.

The typical mid-market apparel brand operates with 15 to 40 interconnected spreadsheets per season. The OTB lives in one file. Each planner maintains their own assortment spreadsheets. Buyers have their own buy plan files. Allocation may be a separate spreadsheet or a module within an ERP. These files share no data model, no version control, and no automated reconciliation.

The consequences are predictable and recurring. Financial plans and buy plans disagree because they were updated at different times. Assortment changes do not cascade to the buy plan because there is no connection between the files. Allocation decisions are made against stale inventory data because the latest receipt information has not been manually entered. And nobody knows which version of which spreadsheet contains the current plan.

Industry research consistently shows that 88% of spreadsheets contain errors. In merchandising planning, these errors translate directly to overbought categories, missed margin targets, and allocation mismatches that generate markdowns.

Spreadsheet-based planning in practice: apparel example

A contemporary women's brand plans its fall season across 22 Excel files. The VP of Merchandising maintains the OTB in a master workbook with tabs for each month and category. Three planners maintain assortment files that reference (but do not link to) the OTB targets. Two buyers maintain buy plan files that reference (but do not link to) the assortment plans.

In week three of planning, the VP revises the knit category OTB downward by $300K based on updated projections. She updates her OTB file and emails the planners. Planner A updates her assortment file the same day. Planner B is traveling and does not update until Thursday. The buyer responsible for knits does not receive the email because she was not on the thread.

Two weeks later, the buy plan for knits is finalized at $300K over the revised OTB. The discrepancy is discovered during a planning review — three weeks after the original revision. The buy plan must be reworked, delaying production commitments and compressing the already tight timeline.

This scenario repeats, in some variation, at virtually every mid-market apparel brand every season.

Common mistakes

Accepting spreadsheets as "good enough." Spreadsheets work until they do not — and the failure mode is silent. A formula error in a buy plan spreadsheet does not throw an error message. It produces a wrong number that propagates through the planning process undetected.

Adding more spreadsheets to solve spreadsheet problems. When the planning spreadsheet becomes unwieldy, the common response is to create a summary spreadsheet that aggregates data from the detailed spreadsheets. This adds another manual reconciliation step and another source of version conflict.

Blaming people for spreadsheet errors. When a planner copies the wrong cell or overwrites a formula, the root cause is not carelessness — it is a system that depends on error-free manual data transfer across dozens of files. The error rate is a property of the system, not the person.

Underestimating the time cost. Merchandising teams operating in spreadsheets spend 30-50% of their time on data management — copying data between files, reconciling versions, building reports from raw data. This is time not spent on the analytical and strategic work that drives margin improvement.