Software implementation is a methodology to effectively integrate a software into a complete service.

There are two programming methods:

-Structured programming is about usisng subroutines and loops to bring clarity to the code and make it easier and faster to read.

-Functional programming uses mathematical functions to operate. With a given argument it should produce the same result.

As you can notice, the main function of these methods is to make the code more easier to read and to understand. Thats why documentation is very important. It helps  future generation of coders to understand what it does without even having to read it completely, also, it makes you the job easier while debugging.

There are several tools that can be very useful to build a program. I´m going to categorize them from the role they play in the process:


-Editor 
The editor is just the text editor. It can go to a simple NotePad or a more elaborated software with integrated features for a specific language like Eclipse.

-Compiler 
The compiler depends on the language you are using. Some check for mistakes while others don´t, it´s main function is to translate the code and convert it into something readable for the machine. There are sevar compilers like GCC for C++ and Delphi for Pascal.

-Debugger 
In case that your editor doesn´t include a debugging tool, you can always check for individual programs that can you to go through each step while running your code and checking for each action and variable individually. Or you can just hire a coder and put him to find bugs.
  
-Profiler
 The profiler measures the complexity and memory usage of your code. It can be a program like cProfiler for Python, NetBeans for Java or AppDynamics for C and C++.

-Tester 
The tester can be another software like JUnit or another person who works as a tester.

-Data storage 
Here can be anything related to data bases or cloud storage like Xammp, MySQL, OpenStack etc.

Keep in mind that not all of these tools are necessary, they just make your job easier and help you to keep your program optimized and bugs free at the very low cost of free and fast.

sources:
https://www.tutorialspoint.com/software_engineering/software_implementation.htm
https://en.wikipedia.org/wiki/Product_software_implementation_method