上游充通大￥ SHANGHAI JIAO TONG UNIVERSITY What is the problem? Your boss:"How long will this take?" You:"Between 1 and 6 months." People are not happy when you respond that way. You figure out that finishing anytime before six months will meet your promise. Your boss figures that with some hard work you can be done in a month! In reality,you don't have the slightest clue how long it will take,because you don't know the work to be done. Solution:Use divide and conquer To give a good answer you have to break the work down into activities for which you can get good timing estimates From these estimates you compute the estimated project duration Software Engineering
Software Engineering What is the problem? Your boss: “How long will this take?” You: “Between 1 and 6 months.” People are not happy when you respond that way. • You figure out that finishing anytime before six months will meet your promise. • Your boss figures that with some hard work you can be done in a month! In reality, you don’t have the slightest clue how long it will take, because you don’t know the work to be done. Solution: Use divide and conquer • To give a good answer you have to break the work down into activities for which you can get good timing estimates • From these estimates you compute the estimated project duration
上充大Activities to obtain good time estimates SHANGHAI JIAO TONG UNIVERSITY Identify the work that needs to be done Work breakdown structure (WBS) Identify the dependency between work units ·Dependency Graph Estimate the duration of the work to be done ·Schedule Software Engineering
Software Engineering Activities to obtain good time estimates Identify the work that needs to be done • Work breakdown structure (WBS) Identify the dependency between work units • Dependency Graph Estimate the duration of the work to be done • Schedule
上浒充通大学 Typical activities when building a house SHANGHAI JIAO TONG UNIVERSITY Surveying Install Wallboard Excavation Paint Interior Request Permits Install Interior Doors Buy Material Install Floor Lay foundation Install Roof Build Outside Wall Install Exterior Doors Install Exterior Plumbing Paint Exterior Install Exterior Electrical ⑧ Install Exterior Siding Install Interior Plumbing Buy Pizza Install Interior Electrical Finding these activities is a brainstorming activity. It is requires similar activities used during analysis(use case modeling) Software Engineering
Software Engineering Typical activities when building a house Surveying Excavation Request Permits Buy Material Lay foundation Build Outside Wall Install Exterior Plumbing Install Exterior Electrical Install Interior Plumbing Install Interior Electrical Install Wallboard Paint Interior Install Interior Doors Install Floor Install Roof Install Exterior Doors Paint Exterior Install Exterior Siding Buy Pizza Finding these activities is a brainstorming activity. It is requires similar activities used during analysis (use case modeling)
上充大Hierarchical organization of the activities SHANGHAI JIAO TONG UNIVERSITY © Building the house consists of Prepare the building site Building the Exterior Building the Interior Preparing the building site consists of ● Surveying ·Excavation ·Buying of material Laying of the foundation ·Requesting permits Software Engineering
Software Engineering Hierarchical organization of the activities Building the house consists of • Prepare the building site • Building the Exterior • Building the Interior Preparing the building site consists of • Surveying • Excavation • Buying of material • Laying of the foundation • Requesting permits
h 上游充通大￥ Partial Work Breakdown Structure SHANGHAI JIAO TONG UNIVERSITY Build Foundation Build Structure Build Walls Build Roof Install Sewer Pipes Build House:WBS Install Plumbing Install Cold Hot Water Pipes Install Tubs Sinks Install Heating Install Electric Software Engineering
Software Engineering Partial Work Breakdown Structure Build Foundation Build Walls Build Roof Install Heating Build Structure Build House:WBS Install Plumbing Install Sewer Pipes Install Cold & Hot Water Pipes Install Tubs & Sinks Install Electric