If the project schedule starts to slip it can be

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functionality in the system. If the project schedule starts to slip, it can be readjusted by removing functionality from the version or prototype under development. The waterfall model is the worst choice, because it does not allow for easy schedule changes. Schedule visibility One of the greatest challenges in systems development is knowing whether a project is on schedule. This is particularly true of the structured methods because design and implementation occur at the end of the project. The RAD models move many of the critical design decisions to an earlier point in the project to help project managers to recognize and address risk factors and keep expectations in check.
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40 Methodologies Methodologies Methodologies Methodologies Comprehensive guidelines to follow for completing every SDLC activity Collection of models, tools, and techniques
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41 Relationships Among Components Relationships Among Components of a Methodology of a Methodology
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42 Models Models Models Representation of an important aspect of real world, but not same as real thing Abstraction used to separate out aspect physical (like a model of an airplane) abstract (e.g. in form of mathematical notation or in graphical form) Models in SDLC are graphical: diagrams and charts Project planning and budgeting aids
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43 Some Models Used in SDLC Some Models Used in SDLC
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44 Tools Tools Tools Software support that helps create models or other required project components Range from simple drawing programs to complex CASE tools to project management software
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45 Some Tools Used in SDLC Some Tools Used in SDLC
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46 Techniques Techniques Techniques Collection of guidelines that help analysts complete a system development activity or task Can be step-by-step instructions or just general advice
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47 Some Techniques Used in SDLC Some Techniques Used in SDLC
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48 Two Approaches to System Two Approaches to System Development Development Traditional approach Traditional approach Also called structured system development Structured analysis and design technique (SADT) Includes information engineering (IE) Object-oriented approach Object-oriented approach Also called OOA, OOD, and OOP Views information system as collection of interacting objects that work together to accomplish tasks
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49 Structured Analysis Structured Analysis Define what system needs to do (processing requirements) Define data system needs to store and use (data requirements) Define inputs and outputs Define how functions work together to accomplish tasks Data flow diagrams (DFD) and entity relationship diagrams (ERD) show results of structured analysis
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50 Data Flow Diagram (DFD) Created Data Flow Diagram (DFD) Created Using Structured Analysis Using Structured Analysis Technique Technique
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51 Entity-Relationship Diagram (ERD) Entity-Relationship Diagram (ERD) Created Using Structured Analysis Created Using Structured Analysis Technique Technique
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52 Structured Analysis Leads to Structured Analysis Leads to Structured Design and Structured Structured Design and Structured Programming Programming
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