SOFTWARE SYSTEMS DEVELOPMENT

4: System Design

Simplified view on software product development process

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Project Lifecycle

Project Time Management

Activity Definition Activity Sequencing Activity Duration Estimation Schedule Development Schedule Control

Activity DefinitionWork Breakdown Structure(WBS)

Resource Allocation

Duration Estimation 3 points method

a= the best-case estimate m = the most likely estimate b = the worst-case estimate E = (a + 4m + b) / 6

Activity Sequencing Precedence Diagram Method(PDM)

Schedule DevelopmentGantt Chart

Schedule Control

PV=BCWS - Budgeted Cost of Work Scheduled

AC=ACWP - Actual Cost of Work Performed

EV=BCWP - Budgeted Cost of Work Performed

• In time units: •PV = Planned Work Time for Planned Work •AC = Time Actually Spent •EV = Planned Work Time for Work Done

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Some Derived Metrics

SV: Schedule Variance (BCWP-BCWS) A comparison of amount of work performed during a given period of time to what was scheduled to be performed.

A negative variance means the project is behind schedule

CV: Cost Variance (BCWP-ACWP) A comparison of the budgeted cost of work performed with actual cost.

A negative variance means the project is over budget.

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SPI: Schedule Performance IndexSPI=BCWP/BCWSSPI<1 means project is behind schedule

CPI: Cost Performance IndexCPI= BCWP/ACWPCPI<1 means project is over budget

CSI: Cost Schedule Index (CSI=CPI x SPI)The further CSI is from 1.0, the less likely project recovery becomes.

Some More Derived Metrics

SoW: Statement of Work

Deliverables: What will be delivered? Brief description (source: SRS)

Activities: What should be done? Brief Description (source: WBS)

Timeline: When it will be done (Milestones)? Milestones Dates (source Gantt)

Assignment: Project Plan

Project Management Team vs. Development Team Customer plays PM role Jointly define the scope with development team

WBS Stop when work package can be reliably estimated Don’t forget non-coding activities (testing, bug fixing)

Gantt Chart Milestones/Deliverables each week Dependencies, time and resource allocation

SoW 2 page brief Project/Milestones scope

Weekly reports by PM team

Each week after the project kickoff PM team: project status and metrics (10 minutes) Development team: milestone demo (10 minutes)

Project Start Date: 23/05/2010 Duration: 4 weeks

Reduce scope if needed.