Connecting an ERP: common mistakes and how to avoid them

An order shows as confirmed in one tool, but not in the ERP. A customer is duplicated. The team corrects data manually in order to issue invoices. When you connect systems without clearly defining what information moves, when it moves and under which rules, the problem does not disappear: it may simply move faster from one tool to another.

This article explains what you should aim to achieve when connecting an ERP, the mistakes that commonly prevent it and a practical way to review the integration before going live. By the end, you will be able to decide whether your case is ready for automation or whether you first need to organise the process.

What you are trying to achieve when connecting an ERP

Connecting an ERP means enabling it to exchange information with another tool or system: an online store, an internal application, a sales platform, a warehouse system or a form, for example.

The aim should not be to “connect for the sake of connecting”. It should be to solve a specific need, such as preventing the team from entering an order twice, keeping certain data up to date or ensuring that the required information reaches the responsible department.

Before choosing a technical solution, separate three considerations:

• Objective: what situation needs to improve and how you will know it has improved.
• Scope: what data, people, actions and exceptions are part of the connection.
• Solution: how information will be exchanged between the systems.

This separation prevents you from choosing a technology before knowing which process it needs to support.

Common mistakes when connecting an ERP

1. Starting with the tool instead of the workflow

Symptom: the conversation begins with a question such as “can the ERP be connected to this application?”, but no one has described what happens from the moment an order, customer or invoice is created.

Cause: the technical possibility of linking two tools is confused with the operational need the connection must address.

Consequence: you may automate steps that add no value, leave out a necessary approval or transfer data before it is complete. It also becomes difficult to decide what should happen when there is an exception.

Correction: map out the actual journey using simple actions: who starts the process, what data is created, who reviews it, which system should receive it and what final status you expect. You do not need a complex diagram; a clear sequence will often reveal ambiguous steps.

For example, in a hypothetical scenario, it is not enough to state that an order moves from a store to the ERP. You need to decide what happens if the customer already exists, delivery information is missing or the order is pending validation.

2. Not deciding which system is the source for each data item

Symptom: the same customer, product or status can be changed in more than one system, without a rule determining which one takes precedence.

Cause: it is assumed that two tools will interpret and update information in the same way.

Consequence: duplicates, overwritten changes and records that appear correct on one screen but not on another start to appear. The team loses time checking which version is valid.

Correction: assign a primary source to each type of data. For example, one system may be the source for new customer records and the ERP may be the source for administrative information. The rule will depend on your operations, but it must be documented and known by those who use both systems.

Also include which fields can move in each direction. A bidirectional integration —where both systems write data— requires more precise rules than one-way data transfer.

3. Relying on field names that look the same

Symptom: fields have similar names, such as “customer”, “reference” or “status”, and are connected directly without reviewing what they represent.

Cause: it is assumed that similar names have the same meaning, format and conditions of use.

Consequence: data may arrive incomplete, be assigned to the wrong field or lead to incorrect decisions. A commercial status, for example, may not mean the same as an administrative status.

Correction: prepare a data map. For each relevant field, specify:

• name in the source and destination systems;
• operational meaning;
• expected format;
• whether it is mandatory or optional;
• transformation rule, if any;
• person responsible for validating the result.

If you use an API —a technical channel that allows two programs to exchange information—, this map is still necessary. The technical connection does not, by itself, resolve the meaning of the data.

4. Ignoring incomplete, duplicate or outdated data

Symptom: the connection works with clean test records, but fails when it receives real-world information with empty fields, different formats or duplicates.

Cause: the workflow is designed only for the ideal case and the quality of existing data is not reviewed.

Consequence: the ERP may receive records that cannot be processed, or the integration may stop without the team understanding why. If the system tries to complete or correct information automatically without a validated rule, it may create further confusion.

Correction: define the minimum data each process requires and what will happen if it is missing. Decide whether the record is rejected, left pending review or saved without moving on to the next step. Also check for duplicate customers, products or references before synchronising them.

An integration should not be used as a substitute for a business decision. Rules concerning sensitive, accounting, commercial or compliance data must be validated by the responsible people.

5. Automating without defining exceptions and errors

Symptom: what should happen when everything goes well is described, but not what to do if a tool does not respond, data is invalid or a submission is repeated.

Cause: the workflow is viewed as a continuous line, without considering that external systems and data can fail.

Consequence: some records may be left in limbo. The team discovers the problem late, does not know what action to take or re-enters information manually without knowing whether it will later be duplicated.

Correction: define exception cases before activating the connection. At a minimum, answer these questions:

• How is a failed submission identified?
• Who reviews the issue?
• Can it be retried without creating duplicates?
• Where is the error recorded?
• When should a person intervene?

A useful control does not only consist of receiving alerts. It must allow you to locate the affected record, understand the reason and decide how to correct it.

6. Granting access without reviewing permissions and responsibility

Symptom: generic credentials are shared or the integration is granted more access than it needs.

Cause: technical access is treated as a configuration detail rather than a decision about who can view, create or modify information.

Consequence: the risk of unwanted changes increases, and it becomes more difficult to identify which account performed an action. In addition, a change to permissions can break the workflow if it is not documented.

Correction: define which actions the connection needs to perform and grant only those permissions. Identify who manages the accounts, who can change the configuration and what will happen if a password, permission or user account is modified.

Also document the access required to maintain the integration. A connection that no one can review or update depends on one person or provider without a clear handover.

7. Testing only that “the data arrives”

Symptom: you confirm that a record appears in the destination system, but not that it was created with the correct data or that the subsequent process works.

Cause: a basic technical test is confused with a complete operational test.

Consequence: the connection appears to be complete even though it creates incomplete records, incorrect statuses or additional work for the team. The error is detected only once it affects day-to-day operations.

Correction: establish verifiable acceptance criteria. For each relevant workflow, define the initial situation, the action, the expected result and the behaviour in the event of an error.

A hypothetical example: when a valid order is created in the source system, it must appear only once in the ERP with the agreed fields and defined status. If mandatory data is missing, the order must be identified for review and must not proceed as though it were complete.

8. Not assigning maintenance or review responsibility

Symptom: the integration is activated, but no one is responsible for reviewing incidents, process changes or modifications to the connected tools.

Cause: the connection is considered a completed task, even though it depends on rules, access and systems that can change.

Consequence: a change to a field, permission or process may go unnoticed until it creates an operational issue. Informal adjustments also accumulate without anyone documenting them.

Correction: assign internal responsibility for operating the workflow. That person does not have to resolve technical issues alone, but they should know what is connected, what information is exchanged, where errors are reviewed and who is responsible for validating changes.

How to prevent these mistakes before integrating

Prevention starts with a small, verifiable scope. Choose a workflow with a clear objective, for example, transferring a specific type of order or updating a defined data item. Then agree on what is outside that first phase.

For each workflow, document:

1. the trigger: which event starts the exchange;
2. the data sent and received;
3. the system that is authoritative for each data item;
4. the prior validations;
5. the exceptions and the person responsible for resolving them;
6. the test that will confirm the process works;
7. the person responsible for maintaining the connection.

This preparation also helps you choose the right solution. Sometimes automation between tools is enough; in other cases, business rules, permissions or the need for a custom interface require a more specific solution. The decision should be based on the workflow and its constraints, not on a technical label.

ERP connection review checklist

Before activating an integration, check the following:

• I have defined which operational problem the connection must solve.
• I have defined the first workflow to be automated.
• I know which system is the primary source for each relevant data item.
• I have reviewed what each field means, not just what it is called.
• I have decided how to handle empty, invalid or duplicate data.
• I have defined what happens when a submission fails or is repeated.
• Access permissions match the actions required.
• I have tested normal and error cases using clear criteria.
• One person is responsible for reviewing incidents and changes.
• Business decisions affecting invoicing, customers or compliance have been validated by the relevant people.

If you cannot complete several of these points, the next step should not be to add more automation. First, it is best to clarify the process and the rules it must follow.

Next step

Connecting an ERP adds value when it reduces a specific task without losing control over data, exceptions and responsibilities. If you are clear about the objective but do not know how to turn it into a secure, maintainable workflow, you can tell AVSISTEC about your automation and integration project to assess the technical scope required.