Visual tool to map relationships between Excel parameters

[excelwizard]

Hi, I am currently trying to build a complex bottom-up financial model for a company and wanted to ask whether there was any visual mapping tool that can help me map relationships between data using an intuitive graphical interface. The financial model I am trying is for a holding company with five subsidiaries. Each subsidiary has its own revenues and costs (including its own employees). The holding company is a cost center with costs and no revenues. I need to run *what-if* analysis and need to be able to recommend an optimal structure to maximize holding company value. I fear that programming this model using basic excel formulas might be too simplistic and limiting. Because there are many relationships between different parameters across the model, I am looking for a tool that can help me map relationships, set rules for different parameters and run simulations to help me *see* the impact of different scenarios on the holding company's financial results. I would be extremely grateful for any recommendations on which (paid or open source) tools, programs or add-ons I can use to support me in this project. Thank you in advance for taking the time to answer this post.