Sales
Orders carry the product, quantity, price and commitment that purchasing, production and invoicing will use later. The promise to the customer enters once.
Production & costing
Replacing a legacy ERP without losing the truth
The old ERP was accurate but immovable. Every exception escaped into a spreadsheet until the system of record and the shop floor told different stories. We rebuilt the operation without losing the accounting discipline that made the old system trustworthy.
- Sector
- Manufacturing
- Replaced
- A rigid legacy ERP, and the spreadsheets beside it
- Core
- Sales · Purchasing · Production · Stock · Costing
- Model
- Documents post movements; balances are derived
The situation
The numbers were right. The operation had moved on.
- Production tracked beside the system
- Stock and cost explained by hand
- Every exception becoming a workaround
- Management choosing which answer to trust
The manufacturer trusted its legacy ERP for a good reason: the ledger balanced. Stock, purchasing and cost followed rules people had depended on for years. Replacing it carelessly would trade one kind of pain for something worse — a modern interface nobody could trust.
But the business had changed around it. New products, exceptions and production decisions did not fit the old screens, and every change meant fighting the system. So the real workflow moved into spreadsheets, paper notes and conversations beside the machine.
Now there were two versions of the company. The ERP held the official answer. The shop floor held the current one. Every production question became a reconciliation, and every useful report arrived after someone had rebuilt reality by hand.
The quiet failure
An ERP nobody can change does not remain the system of record. It becomes one more opinion about what happened.
Starting point
A dependable ledger surrounded by workarounds.
The failure was not that the old ERP calculated badly. It was that the operation could no longer express itself inside the model. People created the flexibility they needed outside it, then paid for that flexibility every time information had to be reconciled back into the official record.
- Sales and purchasing documents that could not follow the current workflow
- Production plans maintained in spreadsheets beside production orders
- Material movements recorded after the fact instead of where they happened
- Stock balances that required a person to explain the exceptions
- Cost reports trusted only after a manual reconstruction
- Changes avoided because adapting the ERP felt riskier than another workaround
How it started
Follow one order until it becomes money.
A manufacturing system cannot be designed one department at a time. We traced the same order through sales, purchasing, materials, production, stock and cost, watching where the meaning changed and where somebody had to type the same fact again. That exposed the real system: not the screens, but the chain of decisions underneath them.
- 01
Trace the physical flow
We followed materials from demand to purchase, receipt, production, consumption and finished stock. Every handoff where the system lagged behind the floor became visible.
- 02
Trace the financial effect
For each operational document, we mapped what it changes: quantity, value, obligation, cost and margin. The goal was not merely to preserve totals, but to preserve why they were true.
- 03
Name the business together
Sales, purchasing, production, warehouse and accounting had different words for the same events. We settled those meanings before turning them into data structures or screens.
- 04
Prove the difficult cases first
Prototypes started with corrections, partial receipts, substitutions and period boundaries — the cases generic demos hide and real operations live with.
Architecture
Keep the discipline. Remove the rigidity.
We did not copy the old screens. We preserved the principle that made the old ERP reliable: documents post movements, and balances are calculated from those movements. A receipt changes stock. A production document consumes material and creates finished value. A sale creates both an operational and financial effect. The interface can change with the business because the accounting truth lives underneath it.
- Documents record business events; they never store a second, editable version of their effects
- Stock, cost, receivables and margin are derived from posted movements
- Corrections create an auditable counter-movement instead of rewriting history
- Cost calculation is isolated in pure, tested rules rather than buried in screens
- Period snapshots keep reporting fast without creating balances that can drift
- Every report can be traced back to the operational documents that produced it
What moved in
One operation, without the reconciliation ritual
Each team gets a view shaped around its work, but nobody maintains a private version of the facts. A change made where the work happens becomes the answer everywhere else.
Purchasing
Purchase demand comes from what sales and production actually require. Receipts update the same material record instead of starting another spreadsheet.
Production
Production orders connect planned output to the materials consumed and the finished goods created, including the exceptions that happen on a real floor.
Stock
Every receipt, issue, transfer, consumption and completion posts a movement. On-hand quantity is the result of what happened, not a number somebody edits.
Costing
Material and production cost flow from the same documents as the physical work, so margin can be explained instead of merely reported.
Reporting
Operations and finance read the same ledger at different distances: what needs attention now, what the period cost, and where the business is making or losing money.
Operational complexity
The difficult part was not replacing screens. It was preserving accounting truth while making the operation easier to change. Stock on hand, unit cost, receivable balance and gross margin cannot become editable columns — columns drift, and once they drift nobody trusts the report. The replacement had to feel flexible to the people doing the work while remaining strict about the movements underneath it.
Systems approach
We rebuilt sales, purchasing, production, stock, costing and reporting around one posting engine. Work is captured in documents people recognise; each document posts explicit movements; every balance is derived. Cost rules live in pure, tested functions, and period snapshots keep the system fast. The business can change the workflow without negotiating with the integrity of the ledger.
Scope
What it involved
- Sales and purchasing documents
- Production orders and materials
- Stock movements and balances
- Cost calculation engine
- Operational and financial reporting
- Migration from the legacy system
Working principle
The breakthrough is not one feature. It is making every answer come from the same event.
Questions we get asked
Before you start a project like this
The questions below come up in almost every first conversation. If yours is not here, it is a good thing to open with.
- Why not buy another manufacturing ERP?
- That is the first option to test. A packaged ERP is the right answer when its operating model fits the business. Custom becomes valuable when the company keeps paying for the mismatch — duplicate entry, side spreadsheets, constrained workflows and reports that need explanation — and those differences are part of how the operation actually works.
- How do you replace a trusted system without losing trust in the numbers?
- By treating accounting behavior as a constraint, not a feature to recreate later. We map what every document changes, implement those posting and costing rules independently of the interface, test difficult historical cases, and reconcile migrated balances before the replacement becomes authoritative.
- Does everything have to move at once?
- No. The sequence follows dependencies. The shared ledger and core documents come first; operational areas move when the records beneath them are stable. The old and new systems can be reconciled during transition, but there must be an explicit answer for which one owns each fact.
- What happens to the spreadsheets people rely on?
- We find out what job each one is doing. Some contain real workflow the ERP never supported and should become part of the new system. Some are reports that should be generated from the ledger. Some are temporary calculations. The goal is not to import every tab; it is to remove the reason the tab had to exist.
- Can a custom ERP adapt without becoming another legacy system?
- Only if the stable rules and the changeable workflow are separated. Posting, audit history and costing remain strict. Screens, approvals, documents and reports can evolve around them. That is what lets the system change with the operation without making its numbers negotiable.
Start with the operation
Talk about your operation.
Every engagement starts the same way, whatever the industry: understanding how the work actually happens.
Show us how it works →