MIS Module 4: Systems Development

what is systems development? why learn it?

step-by-step process used to develop & manage an information system; helps ensure systems are properly planned, developed, tested, & implemented to reduce the chance of failure

SDLC phases

planning, analysis, design, development, testing, implementation, maintenance

planning

define system to be developed , set project scope, develop project plan (gannt)

analysis

gather business requirements, prioritize requirements

design

design system model, design technical architecture

development

build technical architecture, build database & programs

testing

write test conditions, perform testing (unit, system, integration, user acceptance)

implementation

write detailed user doc, provide training for system users, choose an implementation method (parallel, plunge, pilot, phased)

maintenance

build a help desk to support system users, provide an environment to support system changes

how are component based methods (rapid application development) different from SDLC?

SDLC: follows linear, step-by-step process & develops system from scratch component based: use reusable components to build the system faster instead of starting from scratch

agile philosophy?

emphasizes working continually w/ goal of more frequent product rollouts & constant improvement across smaller components of a larger project

prototyping

iterative, exploratory process whereby a preliminary version of the system is built & refined - in response to user feedback before full scale implementation (hot cold)

prototyping useful

helps users see & test system early & identify needed changes

prototyping advantages

encourages active end-user participation, helps resolve discrepancies among end users, gives end users a feel for final system, helps determine technical feasibility, sell idea of proposed system

prototyping disadvantages

may lead to ppl to believe final system will follow shortly, tempt project team to forgo proper testing: documentation, project can be hard to terminate (sunk cost fallacy)

when to use SDLC?

when requirements are clear and/or stakes are high

when to use prototyping?

when requirements are fuzzy feedback is critical

self sourcing

when employees/users (end user) develop info system themselves instead of outside developer

when is self sourcing a good idea?

system is simple, low risk, and users understand business ness

outsourcning

hiring outside company or developer to develop or manage an info system

when is outsourcing a good idea?

outside provider has more expertise or resources than the organization

SaaS

software as a service model offers a full service software suite online

PaaS (platform as service)

slightly more basic, providing firms w/ tools to develop, test & deploy cloud based software themselves

IaaS (infrastructure)

most basic, providing firms w/ only the essentials

SaaS, PaaS, IaaS compared to tradirional outsourcing

all three use an outside provider, cloud services are typically more flexible and scalable because you access resources over the internet instead of having the provider build/manage a custom system for you

primary benefits of SaaS, PaaS, IaaS

lower costs/upfront investment, scalability, less maintenance, quick access

primary risks of SaaS, PaaS, IaaS

less control, dependence on provider, security/privacy concerns

how was three mile island failure different from sinking of vasa?

3 mile: failure of complex system —> predictably unpredictable

vasa: failed output of a poorly developed system

how is the challenger explosion similar to & different from three mile island?

both were failure of complex systems involving human/organizational decisions; three mile nuclear plant safety measures prevented worse outcome & challenger destruction of spacecraft & loss of crew

project definition failures

stem from unclear purpose, weak sponsorship, or misaligned priorities

project failure most relevant phases

planning (what problem) & analysis (what does the system need)

project management failures

reflect deficiencies in planning, monitoring, communication and/or control

scope creep

project expands beyond initially stated goals (from users)

future creep

project adds a feature beyond initial requirement (from developers)

why might teams skip or minimize steps?

poor project management can lead to key development phases being skipped or minimized to cut time/cost (cost/time pressure can lead to lapses in good judgement/ethics)

project execution failures

involve technical missteps in engineering & testing of project —> inappropriate technical choices, inadequate testing procedures should catch flaws before major rollout

how do we cope with a rapidly changing technological environment?

anticipate future changes, pay attention to current ones, know your industry/field

vasa case

project definition failure - ship was poorly designed because requirement/design were wrong from beginning

healthcare.gov

project definition: requirements were unclear/changing

Management: poor leadership, coordination & oversight

execution: inadequate testing & technical problems