Third-Party Application Maintenance

With NSI Belgium, corrective and progressive computer maintenance can help you meet all your ambitions

NSI reworks and maintains your business applications!

Our Third-Party Application Maintenance approach (TMA) guarantees you that your existing app is working as it should and is properly maintained. We aim to guarantee its operation and scale it while maintaining high quality levels.

NSI, long term collaboration

Bertrand Lejeune, Segal Director

“We work together on a wide range of projects from implementing professional software to developing apps for production management and for managing production processes (level 2), including setting up interactive collaboration software.”

Which applications fall within third-party application maintenance ?

All applications, whether specifically developed or based on a software package, are likely to require maintenance. Our computer maintenance experience in French-speaking Belgium helps us take all your applications in Application Maintenance (TMA) for correction and/or development.

Why choose corrective and progressive Third-Party Application Maintenance?

More flexibility

La maintenance applicative offre la flexibilité

The life of a company involves changes and developments: companies merge their solutions, the markets grow, and sales teams expand.... It is therefore natural that support for a solution also undergoes changes.


La TMA avec NSI répond au besoin de qualité

Successful corrective and/or progressive maintenance involves regular, well-paced communication between IT services, the ‘Business’ and NSI. This project phase is intense and will determine its quality.


La maintenance applicative NSI, synonyme de réduction des coûts

NSI commits to implementing a cost control policy. This is particularly noticeable in our capacity to meet customer requests regarding fixed prices or transparency when working on a cost-plus basis.

Improving longevity

 NSI Belgique, maintenancier informatique

As an IT maintenance provider, NSI will implement a dedicated structure and guarantee the longevity of its service by maintaining skills at its heart, the only way of offering long-term service continuity.

Four-phase life cycle of a standard Application Maintenance project

Cycle de vie d'un projet de maintenance applicative (TMA)


App knowledge acquisition phase

NSI acquires relative knowledge on the application:

  • Devising a project plan
  • Analysis of the existing code
  • Documentation of the existing operational procedures
  • ...

Implementing the service

This ‘transition’ phase ensures that the NSI support team’s technical and functional knowledge is boosted.
To do this, NSI drafts a series of documents for the support service centralising the information produced in the project development phase.
After this phase, NSI presents a detailed support implementation plan to the Customer (organisation, full set of batches, tasks, responsibilities, calendar, key dates) and the chosen resources will be validated by common accord.

Operational maintenance

This covers the smooth running of the following activities:

  • Corrective Maintenance;
  • Progressive maintenance (PM), adaptive maintenance (AM) and preventive maintenance;
  • The application support (user and operation);
  • Training and support for change;
  • Actions for methods / quality control;
  • Maintenance administration.

Service reversibility phase

The reversibility stage must allow the Customer or a designated third party to walk back the maintenance of all or part of the applications being maintained. The duration of the reversibility phase depends on the given scope.

The key to successful corrective and progressive maintenance

Technical Expertise

Fast reactions


Why NSI ?

Professional knowledge

Our workers’ empathy is a decisive factor in NSI’s relationships with its customers. IT refers to technology of course but also, and above all, the business. Good knowledge of this is key to helping us complete our mission.

In close cooperation

We would like to be a long-term partner and commit to you. We work on mutual trust: it’s hard-wired into our company!

Continuous improvement

Based in Wallonia and Brussels, our teams offer you a proactive approach associated with continuous development.

Technical expertise

The size of NSI and its experience in IT maintenance make it a particularly fruitful hotbed for skills and know-how.

Would you like more information on our offer?

Let us know about it.