To change the technologies necessary 2 main resources: money and time. Moreover, time is also converted into money. In order to obtain these resources need:
1) Clearly understand the purpose for what you intend to do.
I want to clear it all up, everything to be monotonous and the maximum is transparent and modern.
is not the goal. A reasonable person under it will not allocate resources. All will remain as it is until you identify another goal. Examples of valid purposes in this case: a) Reduce the cost of product development b) Reduce the cost of quality (this is the case when the zoo technology can maintain quality at the proper level).
2) depending on the purpose, you will have to do rough calculations: to evaluate the expert way how many losses, due to old technology, you have per unit of time (day, week, month) in comparison with those, as if it was all already written in a new way. Losses can grow over time. Put on the timeline - get the schedule savings.
3) Calculate the investment required for the replacement project technologies: planning, rewriting, integration, testing, documentation, management, training, etc. Make a timetable of the project, including necessary funding.
4) Dock schedule savings from the date it is received schedule of cash flow investing. Provide risk analysis for cases of "remake" and "leave as is". Further, the project sponsors will conduct regular analysis of the investment attractiveness of the project and will tell you whether the game worth the candle.
5) If you do not give money - change approach to the modification and repeat the iteration from step 2.