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    • The Software Maintenance Model (Application Value Management)

      Continued from.. Implementation And Post Implementation In Software Engineering

      Software maintenance is the process of enhancing and optimizing deployed software as well as remedying defects in the software. Here is an example of a constructed house. Due to wear and tear, the delivered house would require continuous maintenance. This would include any of the following:

      • Quickfixes, such as repairing faulty electricity or plumbing appliances.
      • Additional requirements to be added with the changing needs, such as adding an extra floor to the house.
      • Major repairs, which also require in-depth analysis and designing of the solution prior to its execution, such as relaying the air-conditioning for the entire house.
      At the end of this session, you will be able to:
      • Learn about the fundamentals of software maintenance
      • Study the different stages and activities of the maintenance process
      • Know the service-level agreements and their relevance
      • Identify the key issues in software maintenance
      • Learn about the tool, eTracker
      When in operation, defects are uncovered, operating environments change, and new user requirements surface. Software maintenance is defined as the totality of activities required to provide cost-effective support to software. This includes modification of a software product after delivery to correct faults or defects, adapt the product to a modified environment, and incorporate additional features in the application to cater to the new requirements.

      Software maintenance can be categorized as:
      Corrective maintenance: Is a reactive modification of a software product performed after delivery to correct discovered problems and it is also termed as bugfix.

      Adaptive maintenance: Is the modification performed on a software product after delivery to keep a software product usable in a changed or changing environment. It is also termed as enhancement.

      Perfective maintenance: Is the modification of a software product after delivery to improve performance or maintainability. It is also called performance tuning.

      Preventive maintenance: Is the modification of a software product after delivery to detect and correct latent faults in the software product before they become effective faults. This is also termed as bugfix.



      Here is an example of a house built earlier and which requires maintenance at a future point in time. The maintenance person has to initially plan as to how the contract of maintenance would be executed and which areas would be in the scope of the maintenance. He might exclude the electrical maintenance from the contract and he would decide on the team that would be responsible for maintenance and other business issues. After the contract is signed, the architect responsible for the maintenance studies the building plan in detail, including the plumbing layout. Then, the architect passes on the details to the maintenance team. This stage is for developing an understanding of the existing building. Now, based on the request of the customer the house is maintained over a period of time. As discussed earlier, the maintenance can be of the nature of quick fixes or minor repairs, such as electrical or plumbing repairs, a major change, such as repainting the house and incorporation of additional requirements, such as designing the plumbing system or incorporation of air-conditioning in the house.
      When the software is in operation, defects are uncovered, operating environments change, and new user requirements surface. The principal stages of an application maintenance project consist of planning, knowledge transition, and finally the steady state maintenance activities.


      You have seen what an application maintenance process involves. Now, you will know about the model followed by the application maintenance process. The application maintenance model consists of planning, knowledge transition, and service steady state. The planning phase primarily involves understanding the need of the customer in terms of what is expected from the maintenance team.
      This involves a detailed discussion with the client to identify the requirements and finalizing the contract. The activities in this stage are: Business planning at the organizational level: This includes proposal development, estimating for resources and cost, and defining the escalation mechanism. Maintenance planning at transition level: This includes scope definition and the execution process adaptation. And finally knowledge transfer planning, which involves defining the entire methodology to be adopted during the knowledge transfer phase and a detailed schedule of the KT phase.

      For maintaining the existing application developed by another vendor, the maintenance team needs to understand the functionalities and the technical details of the system. Hence, a knowledge transition phase is required prior to the commencement of the maintenance activities. The knowledge transition phase primarily consists of obtaining:
      The knowledge about the application, considered for maintenance, from the client. Guided support under the supervision of the client, and finally a plan defined for transitioning the obtained knowledge to the team for future support. Initially, the application identified for maintenance has to be thoroughly studied by the K T team. This includes a detailed understanding about the business processes that the application caters to and the functions served by the application. This also includes understanding of the technical details about the application, the environment in which the application is operating along with the details of interaction with the interfacing systems.
      Finally, the application inventory is collected by the K T team for providing support in future. After obtaining an understanding of the entire maintenance scenario, the K T team performs the support activities under the supervision of the client's team. This helps in getting familiar with the support activities and also in defining a detailed plan for transitioning the knowledge obtained and subsequently transferring the knowledge obtained about the system to the entire maintenance team primarily at the offshore centre. The infrastructure required to perform the support is also built during the stage and a knowledge repository containing the details of the maintenance project is also built to capture the entire information, learning, and mistakes committed during the execution of the project. This helps in easy transitioning of resources down the project timelines.

      The steady state support involves resolving the service requests sent by the client, optimizing the processes continuously over time. This involves measuring and analyzing the metrics to identify the weaknesses in the process as well as the application being maintained and defining the corrective measures to eradicate the weaknesses. Finally, offering the client value additions identified and obtained over the maintenance period. This includes proactive root-cause analysis of the recurring problems and the necessary measures for improvement. SLA-based measurement also helps in tracking the performance strictly on a defined interval at every level.

      The steady state requests can be classified based on the type of request or the level of support and the size of the request. The requests can be of the following types:

      FIRST LEVEL-Production support, SECOND LEVEL-Bugfix and THIRD LEVEL-Enhancements


      Similarly the bugfix and the enhancements are further classified into Minor, Major, and Super major, based on their size.
      Software maintenance sustains the software product throughout its operational life cycle. Modification requests are logged and tracked, the impact of proposed changes is determined, code and other software artifacts are modified, testing is conducted, and a new version of the software product is released. It also includes training and daily support through: helpdesks that are provided to users, or any documentation regarding the application. The enhancement bugfix request, popularly called the EBR, primarily consists of the enhancement or bug description, technical details, the proposed resolution for incorporating the request, and the results of testing done after the change.
      The set of activities performed for software maintenance in the steady state can be sequentially classified into:

      Modification request, Classification and Identification, Analysis, Design, Implementation of the change in the necessary places, System Testing, Acceptance Testing, and Delivery.

      Based on the size, type, and complexity of the request, one or more of these phases are integrated or eliminated from the execution cycle.

      The workflow shown here actually illustrates the functioning of the onsite and offshore team in a typical maintenance scenario, describing the activities performed for the various levels and type of support.


      Here is a description of different measurement areas and the areas where improvement can be identified over a period of time.

      Here, you will know the term service-level agreement and will see its importance in the maintenance projects. A service-level agreement is a contractual service commitment that describes the minimum performance criteria a provider promises to meet while delivering a service. This is usually in measurable terms. It typically also sets out the remedial action and any penalties that will take effect if performance falls below the promised standard. It is an essential component of the legal contract between a service consumer and the provider.

      Finally, looking into the value additions offered to the client includes implementing an S L A-based management, which keeps a constant eye on the health of the project and gives a measure of the performances. This subsequently leads to the improvement in the areas of productivity, schedule, and finally the cost involved. The root-cause analysis done at intervals helps in identifying the pain areas of the application and hence focuses on correcting them.

      You will now learn about some key issues and challenges faced during application maintenance. The key issues that should be adeptly dealt with for maintaining the software effectively can be classified as:

      • Technical issues, which includes limited understanding, extent of testing possible, and the maintainability or is it maintenance of code.
      • Management issues that include staffing and process-related issues.
      • Cost estimation that adapts the right methodology as parametric or judgmental.
      • Measures with respect to Analysis, Changeability, Stability, and the Testability of the software.
      In this session, you have learned that:

      • The maintenance process fundamentally includes correction of defects, adaptation to modified environment, and incorporation of additional requirements. They are termed as production support, enhancements, or bug fixes
      • Maintenance can be categorized into proactive, reactive, correction, and enhancement. The combination of these categories result in what are termed as Preventive Maintenance, Perfective Maintenance, Corrective Maintenance, and Adaptive Maintenance
      • The three primary stages of maintenance include Planning for transition, Knowledge transition, and Steady state
      • The classification of requests is based on a combination of their size and type
      • A service-level agreement is a contractual service commitment that describes the minimum performance criteria a provider promises to meet while delivering a service. This is usually in measurable terms
      • The key issues that should be adeptly dealt with for maintaining the software effectively can be classified as:
      a) Technical issues, which include limited understanding, extent of testing possible, and the maintainability of code
      b) Management issues that include staffing and process-related issues
      c) Cost Estimation that adapts the right methodology as parametric or judgmental
      d) Measures with respect to Analysis, Changeability, Stability and the Testability of the software


      Next Article:- Umbrella Activities In Software Engineering



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