The application houses data through the use of an SQL database whose tables, columns, and rows can be modified and viewed through SQL queries and commands. The Java API’s used are java server pages which are created through a Java web application. Within the .jsp files the javascript programming language is used to create Database Scripts whose primary purpose is displaying data retrieved from the database in a usable format. Figure 2 is an example of the tables and columns contained within the SQL database.

Figure 2 Interact table and columns

Software re-engineering involves the use of specialized tools and procedures which allow us to break down a program into its original binary code and view the inner details. The reengineering plan will consist of the following phases:

1. Implementation Recovery - This stage involves determining the purpose of the software. By looking at the behavior of a program and how it is built you can predict its rules. As the observation becomes more in-depth and involved the prediction becomes more accurate. The steps involved in in the implementation recovery stage are as follows:

· Browse the existing documentation. This step allows you to learn the original design of the program and its intended purpose (Blaha, 2014)

· Create a modeling tool. This step allows you to determine the development style and the database structure.

2. Design Recovery – During this stage you break down the mechanics of the program. This allows you to break down the source code into a binary format.

3. Analysis Recovery – This stage involves refining the existing model based upon the

observations you have made. The steps involved in analysis recovery are as follows:

· Clarify the design. This step involves removing any design artifacts.

· Eliminate redundancy. This step involves removing duplicate sets of data.

4. Iteration – As is common throughout all software engineering endeavors the design will not be perfect and you will need to backtrack to correct mistakes and oversights

(blaha, 2014).

Some of the benefits of software re-engineering include enhancing features, and fixing bugs, increasing the robustness and security of the design, and helping software testers study viruses and other malicious code. The objectives of the reengineering plan for the CourseMill application will consist of the following:

1. Refactoring the design to provide increases transparency to system administrators. CourseMill stores javascript pages on the application server however currently those scripts cannot be created or viewed by system administrators.

2. Updating the JDBC (Java Database Connection) interface. The current interface produces SQLExceptions on valid SQL queries.

3. Increasing the robustness and security of the design by identifying possible malware and viruses (Richa, 2014).

In the following section the common API’s used in the CourseMill application will be reviewed. In the evaluation the completeness, suitability, and overall design quality will be critiqued. Additionally, diagrams will be created which show illustrate the designated API’s design and identify the entry points into the application. And finally there will be an assessment of the API documentation to include the overall clarity, completeness, and ease of use.

The SCORM (Sharable Content Object Reference Model) API provides a set of technical standards for online learning software. These standards guide programmers to write code that plays well with other learning software. These standards set by SCORM also govern the way the LMS (the CourseMill application) and the software learning products communicate. This allows the CourseMill database to accept a wide variety of software learning products which can be uploaded to the database and then used by others within the CourseMill Application.

The following figure 3 SCORM API Interface class diagram shows the integration architecture which identifies the entry points into the application. The first class is the integration layer which is the interface between the SCORM engine and the CourseMill application. This layer facilitates communications and acts as a buffer to keep the systems separate. The integration layer is the only part of the SCORM API which customizable for the specified LMS. In this class all of the methods are defined but not implemented. The DefaultIntegration class in the middle provides all of the default methods which are standard for all implementations. Finally, you have the ClientIntegration classes which allow you to customer design methods for each client though usually only the default methods are used.

Figure 3 SCORM API Interface

The SCORM API documentation reflects the fact that SCORM isn’t truly a set of standards that were written from the ground up. Instead, the API referenced the industry standards that were already in place and solved part of the problem and then added to the standards to create a complete solution. This complete solution essentially told developers the proper way to use the standards that were already in place. SCORM is widely used and very well documented, however it does have a shortage of features which has caused CourseMill to migrate to a more modern API known as the Tin Can API.

While SCORM is still the most widely used online learning standard, the Tin Can API Which is also known at the Experience or xAPI is quickly replacing it due to the enhanced features and simplified architecture. All of the SCORM content can still be used in a xAPI environment through the SCORM Engine interface architecture which is shown in figure 3. Essentially the xAPI is an evolved SCORM API which is backwards compatible and retains all of the features of its predecessor while adding additional features to include application security, mobile application features, and the ability to transition from a stationary to a mobile platform.

The documentation for the Tin Can API is complete, thorough, and easy to understand. It provides increased encapsulation thereby increasing the simplicity of the standard while increasing the functionality at the same time. As the internet grows from specified desktops and laptops to mobile devices and finally to most electronics (i.e the IOT “Internet of Things”) cross platform becomes vital to a modern API and it is that feature which makes it suitable for the CourseMill Application.

The java API is a general API which provides a full set of interfaces that utilize the Java programming language. In Java the utilization of Interface objects provides a set of common methods that can be called upon by unrelated classes to perform an action with the intricacies of that action being defined by the class that called upon the interface (Jensen, M. 2009). Programming to an interface allows a developer to utilize the object oriented principle of Abstraction which is when only the essential pieces of logic needed to accomplish an action are analyzed and all else is ignored. Achievement of abstraction occurs when the object oriented principle of Encapsulation is followed. Encapsulation is when an interface object represents, and is only tasked with representing, what an object can do while the details of how it does it are ignored. This compartmentalization of logic greatly simplifies programming methods and allows for an easier understanding of complex programs.

The Figure 4 class diagram shows a person wishing to enroll in Coursemill who “is” either a student or professor and “has” an address. In java this is known as the inheritance hierarchy which is a concept in object oriented programming where a new class is created by acquiring a parent class’s existing capabilities. Documentation regarding the Java interfaces can be found at oracle.com with Java arguably being the most well documented API in existence. The Java API is well suited for any application and is the most one of the most widely used programming languages.

Figure 4 Java Inheritance Hierarchy Diagram

In addition to general APIs there are also web APIs which are known as web services. Web Services are a form of communication which allows us to share data between different programs on separate computers which may reside on different platforms. They are composed of multiple pieces of customer developed code and allow two or more web applications to communicate with each other. The advantage of web services is that they allow organizations to reuse code built by others which in turn allows them to be used by IT Systems as services provided over the internet.

To allow these different web services to communicate a set of standards which spells out the interaction between these services has been developed. The most common of these standards is known as SOAP (Simple Object Access Protocol). The SOAP API is a standard for making XML requests online, which defines what the request and response in XML looks like and how to share those messages back and forth. The activity diagram shown below in figure 6 illustrates the activities of a SOAP API.

Figure 5 SOAP API Activity Diagram

EJB Enterprise JavaBeans which is also known as enterprise bean allows for the accounting of data relationships, error handling, transactions, security, scalability, and connectivity. Common problems can be resolved with common solutions through the use of a framework, and JBE was designed to be that framework. It handles the component deployment to let you focus on writing applications. Each EJB can act on its own it contains an interface, performs services for clients, and tracks its own data. The following figure 6 diagram shows the interaction between the EJB API on the client and server side applications.

Figure 6 Java EJB Diagram

The Advantages of EJBs are that they are a common model for building code, they solve many problems in a common manner, and they provide an easy solution for managing components. The disadvantages are the requirement of an expensive application server, often more than is needed for the application, and there are many more flexible alternatives. An expensive application server is already required for the CourseMill application and the flexibility is more than compensated for by the ease of configuration and thorough documentation.

The three attributes that define an API are efficiency, reliability, and maintainability. Efficient APIs allow developers to produce complicated code in less time. Reliable APIs ensure a steady exchange of information between applications. And maintainable APIs allow developers in the maintenance phase of a project to continue to improve the application through updates and patches while maintaining compatibility with other programs. There are factors which both hinder and improve these attributes.

5.1 SCORM API

The requirements of every project will change over time and flexibility is needed to allow room for requirements enhancements and corrections. The goal of the Agile methodology is to manage change rather than prevent it because implementing change coincides with improving the product. To provide this change we will use a framework which addresses the different factors responsible for software project failures. In the following diagram we will show how changes will be introduced based upon their categorization as defective repair or enhancements to a functioning system. All defect repair requests will go through an approval process which determines the cost and time of repair along with the impact to the system. If the impact is of minimal value or not visible to the end user, it will likely be listed very low on the priority list