Application Program Interface, also known as API is a set of commands, functions, and protocols used when building a software developer for a specific operating system. API allows developers to use standard functions to interact with the operating system, so no need to design the operating system from scratch.

One of the largest mobile telecommunications operator in Indonesia provides an API that can be utilized by the user. BINUS creates provide testing consultancy services API owned by this company through two stages of research, namely 1) API installation process test in an application (by the developer), and 2) API functionality stress test (by the end user). Each study provides conclusions and recommendations for improvement interconnected platform API.

In the process of installation of the API, developers say a few things happened. To give a complete picture, the developer also provides opinion regarding the API used. In addition, this study also aims to evaluate the APIs that are embedded in the application whether it is running well or not, and to know in which part the API needs to be improved. The applications used to be tested are bugs free.

Statistical methods used to obtain information related to whether the API is running well or not is descriptive statistics by using the chart/ diagram. If the majority of respondents fail to execute APIs that exist in the application, then the API is still not going well and need to do further research the cause. As for comparing some similar APIs having the same function, a statistical analysis biplot is used. Criteria position adjacent to the API indicates that the API excel in the criteria. However, if the location of the API in a plot far apart on certain criteria, there should be an improvement in the API based on the criteria that far apart in the plot.

Secondly, for end user testing, based on the API functionality, below are several criteria to be used:

A. Six criteria to evaluate the API notifications:

  1. The process of obtaining notifications / instructions
  2. The process of obtaining notifications straightforward / not too long
  3. Notification / instructions appear quickly
  4. Guidelines for the use of language that is easily understood
  5. Display a notification never fail / error
  6. Notification that appear relevant / appropriate

B. Five criteria to evaluate payment APIs:

  1. Display a notification never fail / error
  2. Ease the process of purchasing
  3. The purchase process is straightforward (not too long)
  4. Information measures purchases of items
  5. Purchase items done quickly