How we built a custom Google Sheets ERP in 14 days for SIBECO, a French sanitation company
How Flowbetta built a purpose-built ERP in Google Sheets — three interconnected files covering project management, quoting, and field expense tracking — and delivered it within 14 days.
02: The Challenge
Fragmented data across disconnected spreadsheets.
SIBECO's workflow spans several distinct steps: lead capture, detailed quoting, field execution, daily expense tracking, and invoicing. When each of these stages lived in separate files, the team faced repetitive data entry, inconsistent document formatting, and difficulty calculating per-job profitability in real time.
The team also preferred to stay within Google Sheets — the tools they already knew — rather than adopt a generic enterprise ERP system that would require significant retraining and ongoing licensing costs.
"I am very demanding and professional, so I am counting on you. I expect a real tool with ergonomic interfaces, buttons, automations, and links between files."
03: The Solution
A Google Sheets ERP Built Around Their Workflow
Rather than adopting a generic enterprise ERP, Flowbetta built a custom ERP system directly inside Google Sheets using Google Apps Script. The system consists of three interconnected files — each handling a distinct function — that communicate dynamically so data entered once is automatically reflected across all three.
Because the ERP lives natively in Google Workspace, the SIBECO team adopted it immediately — no retraining, no new software licences, and no external dependencies.
The central project ledger. Every project row consolidates client details, stage status, and financial summaries automatically.
- →Structured project ID sequencing (e.g. 26-0001)
- →Consolidated client and address records
- →Quote amounts and status tracking
- →Deposit and balance payment dates
- →Expense totals automatically pulled from the costing sheet
- →Calculated gross margin and cost coefficient
- →Standardized stage lifecycle (To be created → Paid)
Select a project ID to populate client info, pick items from the price catalogue, and generate standardized PDFs.
- →Standardized price catalogue (BPU) with line items
- →Auto-fills client records on project ID selection
- →Staff and signatory selector for official documents
- →Dynamic row formatting for clean print layout
- →One-click PDF generation with Drive archiving
- →Invoice tab: deposit (acompte) and balance generation
- →SIBECO branding and signatory details integrated
On-site and daily expense recording. Labour, supplies, and equipment are logged by project and synced to the master ledger.
- →Project lookup by ID with automatic verification
- →Daily expense entry by date, category, and cost
- →Labour logs with standard daily rates
- →Material supplier tracking (Point P, Leroy Merlin…)
- →Equipment and vehicle expense logging
- →Per-project cost breakdown and days worked
- →Totals automatically reflected in the ERP master
Cross-Sheet Data Flow
Data entered in the quoting or expense sheets synchronizes with the corresponding project row in the ERP master — no manual duplication required.
Tech Stack
04: The Process
From discovery to delivery in 14 days.
The project ran from initial discovery through to system handoff within two weeks, with SIBECO retaining full ownership of the files in their own Google Drive throughout.
Workflow discovery & scoping call
Initial alignment with the SIBECO executive team to review existing templates, project stages, catalogue pricing, and required Apps Script automations.
Data structure and template review
Detailed walk-through of the end-to-end project lifecycle, document templates, team signatory details, and formula dependencies.
Google Drive permissions and structure
Initialized the 3-file Google Sheets architecture inside SIBECO's Google Drive, ensuring client ownership and access permissions from day one.
Formulas, scripts, and PDF generator
Built the master ledger, catalogue lookup mechanisms, one-click PDF generation scripts, and expense cross-sheet synchronization.
Handoff and video walkthrough
Delivered the finalized system alongside a screen-recorded video guide demonstrating quoting, expense logging, and status tracking workflows.
05: The Impact
An ERP that replaced scattered files with one connected system.
SIBECO replaced their disconnected spreadsheets with a Google Sheets ERP that connects quoting, project management, and field expense tracking in one synchronized system. The team now manages every job — from first quote to final settlement — without re-entering a single piece of data.
Single Project Entry
Each project is entered once and referenced automatically across the quoting and expense sheets.
Real-Time Cost Visibility
Labour, materials, and equipment costs roll up to the ERP master as expenses are logged in the field.
Consistent PDF Documents
Quotes and invoices are generated from a standardized template with embedded company branding and signatory details.
Defined Stage Pipeline
Each project follows a structured status progression from creation through to final settlement.