How to estimate the amount of labor costs of a software developer based on the results of development?

Question

Project management

Good afternoon!
Tell me, please, is it possible to somehow estimate the amount of labor (in time) that was necessary to make changes to the software (based on java + php (pieces) + MySQL, front-end - joomla, mod-X)? The software has already been developed, it is necessary to estimate the amount of labor costs for making changes / improvements.
What information might be needed to evaluate (commits, logs, etc.)?

Answer 1

Since the main part of the system is written in java, the result is presented as an intermediate bytecode (.class files). Jar files are often used, which are essentially ordinary zip archives containing the same bytecode. The bytecode is close to assembler in its structure and can be read and even modified. At the very least, you can use metrics such as the amount of new/changed code, the number of new classes, the number of new/changed methods, and so on. If you wish, you can try to restore the original java code or analyze the bytecode itself: gross discrepancies between the declared cost of the work and the real costs will come out.
Here is an example of how to get the text of the bytecode with the javap command applied to a class file.
Getexample java source code can be done with JD or CFR or other java decompiler.
With PHP and SQL, there should be no problems at all, they are open. All you need is a person who can evaluate "innovations".

Answer 2

In general, no way.
Either believe the one who did it, or put a time tracker that will write the time and take screenshots.

Answer 3

Для оценки существуют проджект менеджеры, которые занимаются организацией эффективного труда команды, следят за временем и приоритетами.
Заказчик может сделать две вещи - нанять эту команду или не нанимать.
То что хотите вы - это отдельный кусок работы, который должен был быть сделан заранее и оценен как стоимость проекта целиком, а временные затраты могут быть разные - в зависимости от квалификации и количества исполнителей.
Идет либо оплата за выполненный проект целиком.
Либо оплата по времени с тарифом.
Все равно вам нужно либо верить исполнителю на слово, либо нанимать другого программиста для приблизительной оценки, а затем договариваться.