Custom ERP for stock, production and attendance.

02 / 08

Stock: receipts, issues, stocktaking and a barcode scanner on your phone

The stock module records what you have, where it is and what it's worth. At goods receipt, the warehouse worker scans the product code with a phone and enters the quantity, and the system immediately raises the stock level and prepares a record for the accounting program. Issuing goods works the same way, just in the other direction.

An ordinary phone camera is enough to read barcodes and QR codes, right in the browser. If your warehouse scans all day, I recommend a handheld scanner that connects to a phone or tablet over Bluetooth and reads faster.

A food wholesaler, for example, needs batches and expiry dates and has to ship the goods that expire first. A spare parts dealer needs bin locations and the ability to reserve a part for a specific order. I build the stock module around whichever of these you need:

• Goods receipts, issues and transfers between warehouses
• Stocktaking shelf by shelf with a phone in hand: the system shows the differences and adjusts them once approved
• Bin locations, batches and expiry dates
• Reserving goods for an order, so the same item isn't sold twice
• Alerts for minimum stock and a suggested purchase order for the supplier
• Stock value by warehouse for management and records for the accounting program

03 / 08

Production planning: orders, capacity and materials

Production planning shows what needs to be made, on which machine or workstation and when, and whether the materials are there. A production order is created from a customer order, and the system works out the materials needed from the bill of materials or recipe and compares them with stock. If something is missing, you see it before production starts.

A joinery workshop makes every kitchen differently, so each order carries its own dimensions and materials, and the plan mainly depends on how many people are in the workshop. A metalworking shop with repeat parts, on the other hand, needs standard routings, operation times and machine load planned weeks ahead. In both cases, people on the shop floor see on a tablet what they should be doing and tick off each finished operation. Management then sees the status of every order without walking the floor.

The production module usually covers the following:

• Production orders linked to customer orders
• Bills of materials and recipes with a calculation of the materials needed
• Capacity of machines, workstations and people, and a plan weeks ahead
• Issuing materials to production and receiving finished products into stock
• Actual hours worked and materials used on an order compared with the costing

04 / 08

Attendance and HR: clock-ins, leave and payroll data

Attendance in the ERP records when employees arrive and leave, their leave, doctor's visits and overtime, and at the end of the month it prepares the data for payroll. I leave payroll itself in a payroll program that its vendor keeps up to date with changes in the law. The data goes into it through an import or in a format that whoever does your payroll already knows.

People can clock in on a tablet by the entrance or on their phone. A service technician in the field logs time directly against the job, so the same record serves both attendance and billing the customer for the work. A manager approves leave requests in the system, and the whole team can see the leave plan.

Attendance contains employees' personal data, so I set up access directly in the database: employees see their own records, managers see their team and HR sees the whole company. I wrote this kind of security layer, through the Eturial agency, for the CRM and client portal of DAU, a Slovak tax and accounting firm. If the system runs on my accounts, we sign a data processing agreement under Article 28 of the GDPR before launch.

05 / 08

Bookings, service jobs and reports for management

Service companies need appointments as well as stock. A customer books a service visit on your website, the appointment goes into the technician's calendar, and when the job is closed the parts used are deducted from stock. I also build booking on its own, as described on the booking system page. A system like that, connected to Google Calendar, runs on this website too, and it's how you book a call with me.

Management reports fill themselves from the data people enter during their normal work, so nobody has to put them together in Excel on a Friday afternoon. Typically they include:

• Margin by order and by customer: the selling price against materials and hours worked
• Stock value and goods that haven't moved for a long time
• Production load and orders that are running late
• Attendance and overtime by department
• Unpaid invoices, if the system reads them from the accounting program

06 / 08

Connecting to the accounting program you keep

A custom ERP doesn't replace your accounting program. Accounting, VAT and statutory reports have to follow current law, and that's the job of the vendor who maintains the program for all its customers. So the ERP sends documents to the accounting program and takes what it needs from it, such as invoice payments.

Invoices can be issued from the ERP or from the accounting program. In Slovakia, from 1 January 2027 VAT payers must, with some exceptions, issue invoices to domestic businesses as e-invoices, so on every project we agree which of the two issues and sends the invoice. How systems exchange data and what happens when a transfer fails is described on the system integration page.

When connecting, I follow what the accounting software vendor has documented:

• POHODA: XML import and export and POHODA mServer
• Money S3, S4 and S5: the API module
• KROS OMEGA: importing documents from XML and Excel
• ABRA Flexi: REST API

07 / 08

Module-by-module rollout and working on a phone

I don't build the whole ERP at once. We start with the module that holds you back most today, for example stock at a wholesaler or production planning in a workshop, and once it's running in practice, the next one follows. People learn one thing at a time, and I build each new module with what we learned from the first.

I migrate data from old spreadsheets or Access when each module goes live. How the transfer and checks work is described on the moving to a new system page.

The system is a web application. It runs in the browser on an office computer, a tablet on the shop floor and a warehouse worker's phone, and there's nothing to install. I design the warehouse and shop floor screens with big buttons for one-handed use, because the warehouse worker has a box in the other hand. I focused both my bachelor's and master's theses at TUKE on UI and UX, and I taught UX design at a secondary IT school in Košice.

If the signal in your warehouse or on the shop floor is poor, tell me right at the start, because it affects how I build the system. When it's more convenient for your people, I can also build a mobile app.

08 / 08

How much a custom ERP costs

The price of an ERP or any other system a company runs on every day depends on the number of modules and integrations and on how much old data needs to be migrated. I split the quote into modules and parts, so you can decide what to start with, and you can start from around €500. The consultation is free, and after the first call you get a specific price and date.

Once you approve the quote or some of its parts, I build a free prototype so you can check that it will work before you make the final decision. You pay 20% when you order and the rest after handover.

By default, I run the system on my own accounts for a monthly fee that covers hosting, backups and updates and comes to tens of euros up to a low few hundred euros a month. I always fix bugs in a system I've built for free, and the other terms are on my About page.

If you'd rather start by solving one specific process, such as orders or reminders, you don't have to begin with a whole ERP. Take a look at business process automation, which usually starts at €500.