Custom web applications
When Excel is no longer enough: custom web applications
Many internal processes start in an Excel file – and that is often the right thing. A calculation, an order list, a planning table: Excel is set up quickly, everyone can use it, and for a small team it is enough for a long time.
At some point the process changes. More people work with it, different versions circulate, macros get more complex, and suddenly the file is business-critical. Then the question arises whether a dedicated application would be the better foundation.
I don't answer that question with a reflexive yes. First I check whether the existing solution can be simplified and stabilised. Only when a web application offers a recognisable advantage do I build it – lean, tailored to the process, and so that you can operate it without me.
Typical starting points
- Several staff need simultaneous access to the same data and the Excel file is constantly locked.
- Quotes or calculations are created in a file that now exists in several versions with different formulas.
- Not everyone should be allowed to see or change everything, but Excel has no meaningful permissions.
- It should be traceable who changed what and when.
- The macros have become so complex that every adjustment is a risk and nobody fully understands them any more.
Who is this for?
Businesses and departments whose internal process has grown in Excel or in scattered files and who need a more stable foundation – without launching a large software project. Typical cases are calculation and quoting processes, internal planning, the management of master data, or workflows that involve several people.
What can be automated
Taking over existing logic
The calculations and rules from your Excel file are transferred into the application, checked and documented in the process. Proven logic is not lost; it just becomes traceable.
Central data storage
Everyone works with the same state. No more versions by email, no locked files and no question of which table is the right one.
User roles and permissions
Who may see, who may change, who may approve – modelled in the application instead of verbal agreements.
Change history
Every change is traceable: who, when, what. That eases queries, audits and troubleshooting.
Connecting existing data
Import and export of Excel files, connections to databases or APIs so the application fits into your existing environment.
Operation without dependency
The application is built and documented so you can operate it yourself or have another provider maintain it. The source code belongs to you.
Excel or web application?
Both tools have their place. The following overview shows how they differ in practice – as orientation, not as a verdict.
| Criterion | Excel | Web application |
|---|---|---|
| Number of users | One person or a small team | Many users, also across departments |
| Simultaneous use | Limited; files get locked or copied | Unrestricted; everyone works on the same state |
| Data storage | In the file itself; versions arise quickly | Central, in a database |
| Permissions | Practically none | Roles and rights per user |
| Maintainability | Good with a simple structure, hard with grown macros | Structured code, versioned and testable |
| Traceability | Changes are hardly traceable | Change history is part of the application |
| Complexity | Quick to set up, but grows uncontrolled | Higher initial effort, stable afterwards |
| Operation | No infrastructure needed | Needs hosting and occasional maintenance |
If the left column describes your process, a well-built Excel solution is usually the better choice. The more points from the right column matter, the more a web application pays off.
When does it make sense?
Makes sense when …
- several people have to work with the same data at the same time.
- permissions, central data storage or a change history are needed.
- the existing Excel solution can no longer be kept stable despite simplification.
- the process has become business-critical and outages would be felt.
Less suitable when …
- a single person or a small team copes well with one file.
- the existing file can be stabilised with reasonable effort.
- existing standard software could already cover the process.
How I work
- 01
Understand the process and the existing solution
I look at how the workflow works today, which logic is in the Excel file and where the actual problems lie. This clarifies whether a web application is the right step at all.
- 02
Define the scope
What must the application do, what not? I propose a lean first scope that covers the core of the process and put a figure on the effort in a concrete quote.
- 03
Implement step by step
The application is built in short steps. Early versions are tested with real cases from day-to-day business so feedback flows in early.
- 04
Roll out and hand over
Data migration from the previous solution, team training, documentation and handover of the source code. On request I accompany the first weeks of operation.
What you get
- A lean web application that models exactly the process in question
- Central data storage with user roles and change history
- Complete source code and technical documentation
- Training for your team and handover for independent operation
Limits
- A web application needs operation: hosting, updates, occasional maintenance. That is manageable, but not zero.
- The initial effort is higher than for an Excel solution. For a process that concerns only one person, it rarely pays off.
- I build purpose-built applications for bounded processes – not replacement ERP systems and not mass-market software.
Frequently asked
- When should Excel be replaced by a web application?
- When several people have to work with it at the same time, versions circulate, permissions or a change history are needed, or the macros are so complex that every change is risky. Before that, it is worth trying to simplify the file. If only one point applies, Excel is usually still the right choice; if several apply, an application becomes sensible.
- Can existing Excel logic be taken over?
- Yes. Calculations, rules and workflow are taken from the file, checked and documented in the process. This often reveals inconsistencies that went unnoticed in Excel for years.
- Where is the application hosted?
- On a server of your choice – in house, with a hosting provider in Germany or in an existing cloud environment. I advise on the choice and set up operation; the decision on location is yours.
- Do I get the source code?
- Yes, complete and documented. You can develop the application further yourself or commission another provider.
- Can several staff work with it at the same time?
- Yes. That is one of the main reasons for moving from Excel to a web application. Everyone works on the same data state without blocking each other.
- How is the application documented?
- With technical documentation for operation and further development, plus a short guide for users. On top of that, your team gets a walkthrough at handover.
Next step
Has your Excel file become too important for Excel?
Describe the process and what no longer works well today. You get an honest assessment – even if it is that the existing file just needs tidying up.