A range of methods associated with system development have developed over the years as one methodology may not necessarily be suitable for all types of tasks. Some of these methodologies include, the waterfall model, Rapid Application Development and agile development. Each approach has its own set of strengths and weaknesses 

The waterfall model represents an abstract description of the systems life cycle where each stage of development flows on from the previous stage, i.e. each stage of development must be completed before the next one can begin. At the end of each stage a review takes place to ensure the project is on the correct path. Following each end of phase review a decision will be made as to whether the project should continue or be discarded. No stages of the waterfall overlap and testing can only take place when implementation is complete. 

Rapid Application Development is a type of incremental model, which means the whole project is subdivided into a series of builds, each of which undergoes its own separate lifecycle, passing through a requirements, design implementation and testing phases. Each of the components of the system are developed in parallel, produced within a given time frame and then assembled to produce a working prototype which is delivered to the user for feedback. The stages of RAD are: 

Business modelling–here a complete analysis of the business is carried out to determine the flow of information 

Data modelling–where data objects are identified and defined and the relations between the data objects are established 

Process modelling – process descriptions for making any kind of addition or modification to a data object or the retrieval of a data object are identified at this stage 

Application generation – the actual system is developed using automated tools to generate code for the final application. 

Testing and turnover – prototypes are tested at each iteration so the overall testing time is reduced in RAD however the application interface and the data flow between the components must be tested thoroughly. 

The agile development model represents a combination of the iterative and incremental models. The main aim of the agile method is the rapid delivery of a working product in response to customer needs. Agile methods divide the process into small incremental tasks which are provided in iterations which last a number of weeks. During each iteration, a series of teams will simultaneously work on planning, requirements analysis, coding, and testing (both unit testing and acceptance testing). 

When organising any software project a number of elements need to be considered. The main elements to be considered by any project manager include: 

Resources – In the development of a computer system these can be considered more specifically as capital, the development environment and personnel such as, system developers, project managers, system analysts, stakeholders and the development environment (including hardware and software). When considering the organisation of any computer project the organisation of personnel includes ensuring the availability of appropriately trained staff and the efficient deployment of appropriate staff across the project elements. 

Constraints – constraints in project management refer to restrictions which are placed on the limitations of the project. These may be in terms of the scope of the project (i.e. limitations placed on the areas to be implemented as part of the project), schedule and cost. The scope of the project will identify the project goals and defines the boundaries of the project, while the schedule will identify a series of deadlines to be met across the project, including the deadline for project completion. Cost is the most obvious constraint and identifies the maximum spend available to the project. 

Risks – risk management is an important part of organising a software project. Some of the main risks to be considered include:– 

• User involvement – not involving the end user at the planning stage can lead to additional or changing requirements at later stage in the project. This in turn can lead to an increase in costs and time delays 

• Scheduling flaws – inaccurate scheduling of tasks and inefficient deployment of staff can lead to the entire project falling behind deadline

• Inflation of requirements – ineffective consideration of user requirements from the outset can lead to more and more new features being identified as the project unfolds, this too can threaten the project timeline

• Specification breakdown – this can happen for many reasons, for example if the development team did not understand the specification or the user did not understand how their requirements were tied to the specification. 

• Staff turnover – the loss of key personnel can lead to project delays 

• Technology – consideration needs to be given to the familiarity of the project staff with the working platform, do they have prior experience with the hardware / software, are the tasks expected from the hardware reasonable? 

Software project management is the management of any project where a piece of software is being planned and implemented. Many project managers use specialised software to support them in the process of project management. Key features to consider when managing the development and delivery of a piece of software include:– 

Monitoring – project monitoring is a key part of project management. It is important that all key activities are monitored so the project manager is constantly aware of progress and able to apply timely interventions in times of difficulty. Project management software can be used to aid the monitoring process. Progress reports from team managers can help provide the project manager with an overview of the project although alternative approaches including regular meetings or diaries can also be used. Based on their findings from such reports the project manager may use that information to help them keep the project on schedule. 

Scheduling – late delivery of projects can be costly and as a results the project manager needs to ensure that key deadlines are met across the scope of any project. Key factors to consider when scheduling tasks across teams of staff include consideration of interdependency of tasks, task sequencing and parallelism, i.e. which tasks depend on the outcome of any other tasks, what order must the tasks be completed in and which tasks can be completed concurrently. Unrealistic deadlines (perhaps established by the client) can be destructive to project progress. Other destructive influences which may impact upon project progression may include among, other things, changing customer requirements which are not them reflected in the schedule and unforeseen human or technical difficulties that were not foreseen. 

Budget – from the outset, budget is a major factor in any software project. Clients will want to know how much the solution is going to cost, and the project manager will need to ensure at all times across the budget that the project costs are not escalating out of control. Budget or available finance places a constraint on the project and will need to take into consideration factors such as man hours, software and hardware requirements, and licensing issues. Where a project runs the risk of running behind schedule, this will invariably have an impact on the cost. A project manager is expected to work within the constraints of the available budget. 

Resources – in any project resources are considered to be the people, equipment, facilities and anything else necessary for the successful completion of the project. Effective scheduling and optimum deployment of those resources is necessary if the successful completion of the project is to be guaranteed. Resources should be allocated based on the priority assigned to each of the project components. 

Version management is the monitoring of changes to a system during the development process and during its operational life. All changes made to the source is tracked, along with who made the change, why, and any enhancements made; this supports the tracking of any changes to the software and also means all changes can be reversed if necessary. This also helps ensure that everyone involved (developers and users) are working on the same systems.