In the following paper we provide analysis on testing procedure and development of software models, and application architecture for investigation of error-correcting codes’ parameters and decoding algorithms. The proposed models can be applied for the development of software for decoding Turbo-Product Codes (TPC). They allow simplifying development process and retrieve universal solution for TPC investigation. The models are described in the Unified Modeling Language (UML) and follow design pattern recommendations. They can be used for software implementation in various programming languages that support object-oriented model. Heatmap visualization tool is supposed to be the main part for visual investigation of the decoding process. In this work, we propose metrics for heatmap organization and explained behavior of the cells to deliver comprehensible presentation of the message state during decoding process. The combination of metric and heatmap component provides effective way to observe impact of each decoding algorithm element on the process and gives abundant information for comparative analysis about algorithm improvements.