Chapter 9.1: The Systems Development Life Cycle (SDLC)

iterative development

consists of a series of tiny projects. It has become the foundation of multiple agile methodologies

bugs

(Part of testing) defects in the code of an information system

methodology

(maintenance) a set of policies, procedures, standards, processes, practices, tools, techniques, and tasks that people apply to technical and management challenges

business requirements

(part of the analysis phase) the specific business requests the system must meet to be successful, so the analysis phase is critical because business requirements drive the entire systems development effort.

waterfall methodology

a sequence of phases in which the output of each phase becomes the input for the next. in SDLC, this means the steps are performed one at a time, in order, from planning through implementation and maintenance.

agile methodology

aims for customer satisfaction through early and continuous delivery of useful software components developed by an iterative process using the bare minimum requirements. fast and efficient, with low costs and fewer features. using this methodology helps refine feasibility and supports the process for getting rapid feedback as functionality is introduced.

Legacy system

an old system that is fast approaching or beyond the end of its useful life within an organization

issues related to the waterfall methodology: the business problem

any flaws in accurately defining and articulating the business problem in terms of what the business users actually require flow onward to the next phase

project scope

describes the business need (the problem the project will solve) and the justification, requirements, and current boundaries for the projec

issues related to the waterfall methodology: the plan

managing costs, resources, and time constraints is difficult in the waterfall sequence. what happens to the schedule if a programmer quits? how will a schedule delay in a specific phase affect the total cost of the project? unexpected contingencies may sabotage the plan

planning phase

phase 1 establishes a high-level plan of the intended project and determines project goals. planning is the first and most critical phase of any systems development effort, regardless of whether the effort is to develop a system that allows customers to order products online, determine the best logistical structure for warehouses around the world, or develop a strategic information alliance with another organization

analysis phase

phase 2 the firm analyzes its end-user business requirements and refines project goals into defined functions and operations of the intended system

design phase

phase 3 establishes descriptions of the desired features and operations of the system, including screen layouts, business rules, process diagrams, pseudocodes, and other documentation.

development phase

phase 4 transforms all the detailed design documents from the design phase into the actual system. the project transitions from preliminary designs to actual physical implementation.

testing phase

phase 5 brings all the project pieces together into a special testing environment to eliminate errors and bugs and verify that the system meets all the business requirements defined in the analysis phase

implementation phase

phase 6 the organization places the system into production so users can begin to perform actual business operations with it

maintenance phase

phase 7 the organization performs changes, corrections, additions, and upgrades to ensure that the system continuous to meet business goals

SDLC phases

planning analysis design development testing implementation maintenance

project management

the application of knowledge, skills, tools, and techniques to project activities to meet project requirements

Systems development life cycle (SDLC)

the overall process for developing information systems, from planning and analysis through implementation and maintenance. the SDLC is the foundation for all systems development methods, and hundreds of activities are associated with each phase. these activities typically include determining budgets, gathering system requirements, and writing detail user documentation

issues related to the waterfall methodology: the solution

the waterfall methodology is problematic in that it assumes users can specify all business requirements in advance. defining the appropriate IT infrastructure that is flexible, scalable, and reliable is a challenge. the final IT infrastructure solution must meet not only current but also future needs in terms of time, cost, feasibility, and flexibility. vision is inevitably limited at the head of the waterfall