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Constraints vs Virtual tabulation

The Configuration Problem refers to the challenge of guiding a user to select values for variables that satisfy all rules in a product model. Two approaches that have been developed to solve this problem are constraint-based systems and virtual tabulation.

In this blog post, we will compare these two techniques and discuss their pros and cons.

Constraint based systems

Constraint-based systems are a popular approach for solving the configuration problem in CPQ. The core principle of this approach is to rely on a set of constraints or rules that define the valid configurations of a product model. These constraints are used to limit the choices available to the user, and a constraint solver is used to find a solution that satisfies all the constraints. This approach is effective in finding a solution, but it can be slow and computationally intensive, especially for large and complex models.

One of the main advantages of constraint-based systems is that they can handle uncertainty and incomplete information. This is useful in situations where the user may not have all the information needed to make a decision, and the system can provide suggestions based on what information is available. This allows the system to be more flexible and adaptable to different scenarios, making it a more versatile approach. Additionally, constraint-based systems can be integrated with other systems in real time, such as ERP or CRM systems, to provide a more comprehensive solution.

However, constraint-based systems also have some limitations. One of the main disadvantages is that they can be slow and computationally intensive, especially for large and complex models. Additionally, they require a certain level of technical expertise to set up and maintain, which can be a barrier for some organizations. Furthermore, these systems may not be as efficient when it comes to providing guidance to the user in real-time.

In summary, constraint-based systems are a powerful approach for solving the configuration problem in CPQ, but they have some limitations. They are effective in handling uncertainty and incomplete information, but they can be slow and computationally intensive.

Additionally, they require a certain level of technical expertise to set up and maintain, which can be a barrier for some organizations.

Virtual tabulation

On the other hand, virtual tabulation pre-computes all possible valid configurations of a product model and stores them in a virtual tabulation file. This file is then used to guide the user to a valid configuration in real-time. This approach is faster and more efficient than constraint-based systems because it only needs to look up a valid configuration in the VT file rather than solving a set of constraints. Additionally, virtual tabulation allows for an easy projection of the set of valid configurations to a subset of the variables which can be inspected in, for example, Excel, which can be useful for analysis and validation of large sets of configurations.

One of the main advantages of virtual tabulation is that it can handle very large and complex models with a high number of valid configurations. This is because the VT file can be pre-computed and stored, making it easy to access the valid configurations in real-time. Additionally, virtual tabulation can provide guidance to the user in real-time, making it a more efficient approach.

However, virtual tabulation also has its own limitations. One of the main disadvantage is that it is based on pre-computing all possible configurations and storing them in the VT file. This means that if the model changes, the VT file needs to be recomputed. This can be time-consuming and may not be feasible for very large models. Additionally, the VT file can become very large, making it difficult to store and access.

Another limitation of virtual tabulation is that it does not handle uncertainty and incomplete information as well as constraint-based systems. In situations where the user may not have all the information needed to make a decision, constraint-based systems can provide suggestions based on what information is available.

What to choose?

In conclusion, both constraint-based systems and virtual tabulation have their own advantages and disadvantages. Both techniques have a solid track record of solving really complex configuration problems.

Constraint-based systems are effective in handling uncertainty and incomplete information, while virtual tabulation is more efficient in handling large and complex models.

The choice of which approach to use will depend on the specific requirements of the project and the trade-offs that need to be made between handling uncertainty and performance.

Vendors

One example of a CPQ solution that uses constraint-based systems is Tacton CPQ. Tacton's approach is built on constraint-based modeling, which allows for easy management of complex product models and easy integration with other systems. Tacton's solution provides guidance to the user in real-time and can handle uncertainty and incomplete information.

One example of a CPQ solution that uses virtual tabulation is ConfigIT. ConfigIT uses a compilation-based approach, where all rules are compiled into a representation of the set of all possible valid configurations called the Virtual Tabulation file. This VT file is then used to support a configurator that can efficiently guide the user to a valid configuration. This approach is faster and more efficient than constraint-based systems, especially for large and complex models.

Next step

Both Tacton CPQ and ConfigIT are well-established CPQ solutions that have been adopted by many companies around the world. If you're interested in learning more about CPQ solutions and which approach might be the best fit for your organization, please don't hesitate to reach out to CPQ experts at cpq.se.

We can provide you with more information and help you determine the best approach for your specific needs.

It is worth noting that Gartner, the world's leading research and advisory company, has recognized Tacton CPQ as a leader for Configure, Price and Quote Application Suites.

The Magic Quadrant is a widely used tool for evaluating the strengths and weaknesses of different vendors in a particular market, and being recognized as a leader in this report is a significant achievement for Tacton. This recognition highlights Tacton CPQ market presence, and overall vision and strategy in the CPQ space.

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