Consolidate hundreds of Excel mapping files without a big-bang project
Count the reference files your company actually has. The number surprises people. Mid-sized companies typically sit between 200 and 1,000 reference files spread across SharePoint, network drives, OneDrive, and email attachments. Most are not actively maintained. Many duplicate each other. A surprising number contain data nobody remembers creating.
The temptation is to consolidate everything at once. That approach almost always fails.
Why the big bang fails
The files are not technically interconnected, but they are organisationally interconnected. Each file has people who care about it. Each of those people has time pressure and other work. A consolidation project that requires all of them to engage at the same time runs for two years and finishes without their attention.
The shape that works is incremental, pain-driven, and patient about leaving old files in place for a while.
The playbook
Step 1. Pick the most painful list. Not the biggest. Not the most strategic. The one causing operational pain right now. Currency codes mismatched across two systems. Customer types that mean different things in Sales and Finance. Cost centres the controller has been complaining about for months.
Step 2. Migrate that one. Move it into a registry. Most platforms, gridmap included, accept CSV or Excel import directly. Identify the owner. Point downstream systems at the registry. Run it in parallel with the old file for a month. Once nobody is reading the old file, archive it.
Step 3. Let the second migration be easier than the first. The team has now built an opinion. They know which lists are next worth moving and which patterns of friction to expect.
Step 4. Repeat until the remaining files are clearly low value. You will not migrate everything. The point is to migrate the ones that matter.
The three categories of leftover files
By the tenth or fifteenth migration, the remaining files fall into three groups.
| Category | Pattern | Action |
|---|---|---|
| Active use | Real owner, active edits | Standard migration |
| Infrequent reference | Annual lists, archives | Migrate when convenient |
| No owner, no edits | Nobody uses, nobody deletes | Tag archived; revisit in six months |
The third group is the hardest because the cost of migrating is real and the value is unclear. Leave them in place. If nobody touches them in six months, archive more thoroughly. If somebody does, that is the signal to migrate.
Mistakes to avoid
Do not inventory everything first. The inventory will take three months and produce a spreadsheet nobody reads. Start with the painful lists; let the inventory emerge as you go.
Do not require agreement on the canonical version before starting. Migrate one version. Make it canonical by virtue of being in the registry. If someone disagrees, they can edit. The conversation shifts from "which file is right" to "what should the registry say", which is more productive.
Do not promise to migrate everything. Some lists belong to teams about to be reorganised or processes about to be replaced. Spending two months migrating those is wasted work.
Do not delete the old files immediately after migration. Leave them in place with a clear note pointing to the new location. People arrive at old files via old links for a year or more. The note saves them an hour of searching every time.
The metric for "done"
The objective is not zero Excel files. It is one authoritative version of each list, with the others marked as archives that point to the truth.
| Wrong metric | Right metric |
|---|---|
| Files eliminated | Questions answered without ambiguity |
| Migrations completed | Disagreements resolved by lookup |
| Inventory percentage | Time from question to answer |
When the right metric moves in the right direction, the consolidation is working, even if the file count has barely changed.