In my opinion, the best option is to contact developers. They don’t necessarily have to create an ERP from scratch for you. Right now the hybrid approach is popular, when companies take ready-made solutions and improve and fine-tune them so they work specifically for you. These ERP systems are very effective for process optimization, and using construction companies as an example, more details here. An ERP system that matches your needs lets you manage all projects at once, see expenses, income, deadlines, budgets, and basically everything happening at any specific site.