Discuss the steps of the systems development life cycle (20Marks)
The systems development life cycle describes a structure that describes responsibilities or functions executed at the different stages in software development. It involves 7 stages which include planning, systems analysis and requirements, system design, development, integration and testing, implementation, operations and maintenance in that order.
Planning being the first stage is the stage where long term or strategic objectives are reviewed in terms of them being achievable. This way, there is need for identification of whether or not it is necessary to make complete changes in the current system of an organisation or just maintain the already existing one. This stage is sometimes called the feasibility study stage. It is a study of whether or not the business has the capacity to make changes within the organisation. A feasibility study is complete when various feasibility aspects are thoroughly taken into consideration. These resources include technical, economic and operational elements. Misjudgements in this stage can lead to total failure of the whole project to be undertaken.
The system analysis and requirements stage immediately follows the feasibility study stage. In this stage, the scope of the problem will be known, basing on the previous stages. This involves information on what the organisation lacks or its inefficiencies. As a result, various documentation tools and dummies are utilised in the attempt to report and envision the probable desired and suggested system. The main aim is to attempt designing of a product or final system which will adhere to the demands of its users. Requirements analysis calls for an integration of hardware, software and engineering competence. Requirements analysis or engineering describes a procedure used for establishing the end user expectancy for the product. This stage leads to the systems design stage.
The system analysis and requirements is an input into the 3rd stage.The system design stage is where the ‘real work’ begins. It involves compiling information that is needs to be transformed into physical existence in the development stage. The design stage is the most critical stage in the systems development life cycle. Various processing descriptions are drawn up. These include, input, output, and coding schemes. Important activities in this stage include the designing of IT infrastructure as well as designing systems models. It also involves the decision of the programming, hardware and software to be used. An organisation may decide to purchase a software and then customise it to suit needs of the organisation. The other alternative is in-house designing where it is developed from scratch. Other elements decided are control processes, limitations on the system, data structures, interface, backups etc.
The development stage now involves utilising the design information collected from the design phase to create the actual or physical system. Data flow diagrams decision trees and flowcharts are some of the many tools used utilised in the designing of the system. In the design stage, the programming language and the hardware and software platform in which the new system will run are also decided. Data structure, control process, equipment source, workload and limitation of the system, interface, documentation, training, procedures of using the system, taking backups and staffing requirement are decided at this stage. Numerous activities take place in the design phase. A few include the following; designing of the application, designing and integration of the network and reviewing final design.
Immediately after systems development stage comes the integration and testing stage. It is done before the release of the end product to final users. It is done so as to check if the designed systems is able to match expectations. Thorough testing is needed before final product is released. Integration testing mainly involves testing of individual components that make up the whole system. Their functionality is tested before they are integrated to make a complete system. If the individual elements or components are tested and prove to work well, they are then integrated to make a complete system. The complete system is then tested to see if the various components combined are working well as a complete unit. Some elements to be tested include safety measures that is, security as well as its rapport or compatibly.
The cycle continues in the implementation stage. The software then moves into the actual producing stage. This means that the software is implemented to work in real situations. Implementation can be done in either three ways. These include parallel, pilot and phased implementation. It is important that the system is properly configured before this stage. This is because when errors are noticed in the implementation stage it becomes costly for the organisation. For example in 2017 Samsung had to recall the Samsung note 7 which it had already released and was in the hands of the end users, its customers. This was because batteries were exploding, indicating lack of proper testing. This then led to the company losing close to 5 billion dollars.
Operations and maintenance is the last stage. It involves the regular monitoring of the system in use. This is done so that the system continues to meet the organisation’s objectives so that it remains competitive. Constant monitoring also gives room for system upgrade so as to maintain the system as well as making complete changes to it. Additional features can also be added to the system depending on the objectives of the business over time. The maintenance stage also helps rectify problems that may emerge regarding the software. It also ensures the system operates at full capacity.
Mistakes at any stage in the SDLC can prove to be very costly to an organisation. Therefore it is very important that the organisation realises its importance and takes time in ensuring that all functions at every level are performed to ‘perfection’.