How CRM ERP Integration Works - Part 2

The second part of the article reports on the requirements and technology of CRM-ERP interfaces and gives you valuable tips for the introduction of such an integration in your company.

Interface Technologies

Modern CRM solutions already come with interfaces (APIs) to connect them to third-party systems such as ERP solutions. These interfaces do not operate on the data layer but on the business layer and provide a number of convenient functions and procedures that can be called outside the applications.

Interfaces can be implemented not only at the function level, but also at the database level. Through such integration, data can be moved between the databases of the CRM and ERP systems, bypassing the function level. This form of integration is very flexible if all data from both systems can be accessed and if current data is always available through reciprocal replication of the database fields. However, precise knowledge of the data model is also required here, as misinterpretations can occur due to the lack of business logic. When selecting a competent CRM provider, particular attention should therefore be paid to its experience in the ERP environment.

Requirements for a CRM ERP Interface

A modern interface between CRM and ERP should basically cover the following aspects:

  • mapping of processes across system boundaries
  • consistency and consistency of data in the participating applications
  • transformation of system-specific data structures and values
  • resistance to data errors and failure of the systems involved
  • no double work in the systems due to simple and fast data comparison


When implementing interfaces, it is important to take into account updates to the ERP system and the CRM system. These can have effects on the function of the interface, for example by changing the data model. A conscientiously managed interface documentation helps to keep track of any adjustments.

What Types of Interfaces Are There at All?

In general one speaks of

  • standard interfaces
  • individual interfaces and from
  • configurable and expandable standard interfaces

Standard interfaces provide an already predefined fixed range of functions, reduce the effort and avoid the development risk of an individual interface. However, they can only be configured and thus not flexibly implemented. This is also not necessary for the classic application areas of a standard interface. Examples are, for example, groupware, office or CTI integration. ERP couplings, on the other hand, are actually never standard and the interface requirements are very often individual. Therefore, the importance of ERP standard interfaces should not be overestimated, adaptations are usually unavoidable.

Individual interfaces offer a freely definable range of functions. However, they require specification effort and the corresponding implementation, so that a calculable development risk must be taken into account.

Configurable and adaptable standard interfaces are based on flexible standard function blocks. The range of functions can be extended. The development risk is comparatively minimized, since the specification and implementation only concerns the adaptation of the building blocks.

Our Advice

Since ERP implementations are rarely a “standard matter”, a configurable, customized interface to the CRM system is most likely the ideal model for a company’s ERP environment.

Advantages and Disadvantages of the Individual Methods

File-based data exchange

  • offers standard tools for XML or CSV files
  • uses the file system as a cache
  • is carried out as asynchronous data exchange

It is used for spontaneous import or export.

+ good performance (CSV)
+ no programming necessary

– low fault tolerance

Table-Based Data Exchange

  • offers direct database access
  • direct access or access via interface tables

It can be used for almost all tasks.

+ optimal performance
+ delayed error handling possible
+ very good system integration

– programming necessary

Data Exchange via Web Services

  • offers cross-platform exchange of data and call of methods
  • is carried out as synchronous data exchange

Used for calling methods in the external system or querying prices, blacklists, and so on.

+ good error handling possible
+ good system integration

– limited performance
– programming necessary

Introduction of a CRM ERP Interface

The implementation of an interface between ERP and CRM should not be done by the way. After all, this is about the interlocking of two strategic applications, the successful integration of which can result in added value in many respects.

A prerequisite for good success is good planning and a detailed definition of the necessary steps. It does not matter whether the CRM provider offers a preconfigured interface to the customer’s ERP system or not.

Integration depth, interface scope and coupling scenarios depend on the requirements and the IT situation of the company. Different types of access, such as access at application or database level, as well as the type of data integration must be considered. Accordingly, a CRM ERP integration can be implemented in many variants. A workshop with your CRM provider to which ideally the IT department but also the affected specialist departments are invited creates clarity.

You should pay attention to the following points in any case.

Data Streams and Data Sovereignty

There must be clear rules for common data. What is transported where (write, read only or display) and above all: Who is the master for which data and processes, i.e. the leading system?

In organizational terms, too, it must be clearly defined which unit is responsible for data maintenance with which system. If necessary, data sovereignty should be defined according to certain classifications up to field level, for example when using contact data also across system boundaries.

Details on Data Preparation and Transfer

Master data that is described down to attribute level is exchanged between the CRM system and the ERP system.

As banal as it may sound: The preparation and comparison of address data – whether for new entry or for migration with the other system – is of fundamental importance. An identical address may only occur once in both systems. In this case, appropriate checking and correction work must be planned in advance, e.g. if the spelling of the same contact or address differs. Take the opportunity to exclude possible duplicates and data redundancy in advance or reduce them to a minimum. Modern CRM systems offer you powerful, parameterizable duplicate management solutions for this.

Error Resistance

In the event of an error, interface monitoring and the behavior in the event of an error must be defined. Thus, error resistance can be guaranteed by marking stored information and automatic resetting after correction.


Regardless of whether a preconfigured, customized standard interface of the CRM provider is used or not, the correctness of the data transfer is an essential point of acceptance for the live operation and should be a milestone: The accuracy of the data is confirmed.

The interface can be tested and tested for release not only by testing the functionality, but also on the basis of a “real” order scenario.

Training and Documentation

The recommended interface documentation describes in detail how the interface works and contains information on exchange tables and field attributes that developers and users need to access. Tip: Don’t forget to note down all relevant contact persons as well as contact data of your CRM provider, the ERP supplier and the colleagues involved in the documentation.

A factor that should not be underestimated is the employees’ acceptance of new ideas. Early involvement of colleagues in the project and appropriate training ensure the success of cooperation across system boundaries.

Follow-up, Monitoring and Verification

With the live operation of the interface, CRM and ERP providers as well as the user company must plan time for queries and small changes.

If the interface is in operation, its use must be checked regularly. If necessary, employees do not use the new functions, bypass the interface and maintain data manually in both systems due to uncertainty! Timely intervention usually helps to eliminate behavioural malfunctions quickly.

Remember that nothing is as constant as change. It will therefore be necessary from time to time to adapt their IT systems and their interfaces to the changing business environment.


A view of ERP data from the CRM system logically offers advantages for sales decisions. Conversely, ERP applications should also be able to access CRM data, because professional customer relationship management can hardly be realized today without a corresponding connection between ERP and CRM systems.

Used correctly as a CRM and ERP duo via an interface, such a “dream team” can boast strengths that offer every company decisive advantages in everyday business processes and over its competitors.

If a decision is to be made on the integration of ERP and CRM, then an already existing configurable and adapted ERP interface of the CRM provider is to be given preference in any case.

Whatever strategy and technology a company chooses with regard to ERP and CRM connection, success is usually not a question of software. The decisive factors are the goal, the usage concept and, of course, especially the people involved, primarily the users in the company but also system partners and consultants.