We are aware of the complexity inherent in LP models and we recognize that complexity can evolve seriously over time: with many people working on the models, with adding new factors, and with attempts to make the model meet more and more requirements. This results in huge performance and efficiency issues, painful operation for the modellers, suboptimal model results, thus ultimately potentially even bad business decisions and financial losses.

On top of this, the experts originally building the model are often not available anymore, either because the model was externally built, or because the colleague has left the company in the meantime.

As with any process, it is much easier to notice potential deficiencies, improvement opportunities from outside, rather than from inside, working with the process, system or tool every day.

Therefore, we strongly believe that a regular model review by an external party is essential in refinery planning and it can bring huge benefits, which are often overlooked and underestimated.

If the above issues are familiar to you and your team, Zanin is here to help.

We offer two levels of Aspen PIMSLP model review, depending on your needs and on the severity of the model issues:

  • Quick overall review of model performance

  • Deep review of all sub-models

Before engaging in any model review project, we perform a free quick-look analysis and provide a free cost-time estimate for the review project.

At the end of the review, we hand over a detailed report with our findings and recommendations for the potential improvements for the model, accompanied by a follow-up call to discuss them.


Our Aspen PIMS™ LP modelling services are a natural continuation to our model review services, where we offer to rectify the issues found during the review, but we are also happy to discuss any other modelling service requirements that you might need.

We are aware that sometimes the internal resources necessary for modelling projects might not be available, due to day-to-day commitments or the lack of necessary skillset in-house. But we are here to help you out with our wide range of Aspen PIMS LP modelling services:

  • Implementation of recommendations resulting from the model review

  • Identification of unnecessary loops and historic redundancies in the model along with their rectification

  • Model performance improvements through structure

  • Model performance improvements through settings

  • Implementation of new structures

  • Periodic model updates and support

  • Any additional modelling services according to your needs

We pride ourselves on always aiming to create simple, easy-to-follow (and easy-to-update, easy-to-modify) structures, and to limit complexity to the absolutely necessary levels. We provide solutions with maintainability and ease of use in mind, guaranteeing a smooth future operation without the need for the future presence of the developer.


We recognise that sometimes even if the models are set up technically correctly and neatly, with good structure and settings, the model results might still be suboptimal, resulting in lost opportunities. It might happen due to existing, but unused degrees of freedom in optimisation, or bottlenecks in the refining process caused by capacity imperfections of certain units which could be improved with minor investments.

Therefore, we believe that a periodic model review going beyond model technicalities, aiming at refinery improvement analysis is also beneficial.

We offer Aspen PIMSLP model reviews for refinery improvement analysis with the following scopes:

  • Identification of unused optimisation space

  • Refinery de-bottlenecking analysis: finding areas where minor investments in increasing or decreasing the capacities of the units could result in significant benefits and higher profits.

Model review and rectification of review findings is a pre-requisite for this service.

See our other products: