Om 411 Estimating Project Times And Costs PDF
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This document discusses project estimation methodologies, including top-down and bottom-up approaches. It also details factors affecting estimation accuracy and the development of project networks. The content covers topics such as direct costs, overhead costs, and activity-on-node (AON) and activity-on-arrow (AOR) approaches.
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OM 411- CHAPTER 5 & 6 PARAMETRIC PROCEDURES APPLIED TO SPECIFIC TASKS- ESTIMATING PROJECT TIMES AND COSTS RANGE ESTIMATING- works best Project...
OM 411- CHAPTER 5 & 6 PARAMETRIC PROCEDURES APPLIED TO SPECIFIC TASKS- ESTIMATING PROJECT TIMES AND COSTS RANGE ESTIMATING- works best Project Estimation – is indeed a yardstick for when work packages have a project cost control. significant uncertainty ESTIMATING – forecasting or approximating the PHASE ESTIMATING- unusual amount of time and cost. uncertainty surrounds a project CLASSIFIED AS: 2 ESTIMATE SYSTEM 1. TOP-DOWN ESTIMATES- done by senior 1. DETAILED ESTIMATE- developed for the management immediate phase 2. BOTTOM-UP ESTIMATES- performed by 2. MACRO ESTIMATE- made for the the people doing the work. remaining phases of the project FACTORS INFLUENCING THE QUALITY OF TYPES OF COSTS ESTIMATES 1. DIRECT COSTS- chargeable to a specific PAST EXPERIENCE- good starting point for work package; can be influenced by the developing time and cost estimates. project manager 2. DIRECT PROJECT OVERHEAD COSTS- PLANNING HORIZON- quality of the resources of the organization being use in estimate depends on the planning a project; can be tied to project horizon deliverables PROJECT DURATION- time to implement Direct overhead rates – pinpoint which new technology resources of the organization are being PEOPLE- can also introduce errors used in the project. PROJECT STRUCTURE AND 3. GENERAL AND ADMINISTRATIVE (G&A) ORGANIZATION OVERHEAD COSTS- costs that are not PADDING ESTIMATES- causes some directly linked to a specific project managers/owners to call for a 10-15% ORGANIZATION CULTURE-can significantly influence project estimates DEVELOPING THE PROJECT NETWORK (CHAP 6) OTHER FACTORS- Project plan – defines project goals and METHODS FOR ESTIMATING PROJECT TIMES & objectives, specific task and how goals will be COSTS achieved. 1. TOP-DOWN APPROACHES PROJECT NETWORK- tool used for planning, CONSENSUS METHODS- uses the scheduling, and monitoring project progress; pooled experience of senior and/or middle project managers CONSTRUCTING A PROJECT NETWORK RATIO METHODS- (TERMINOLOGIES) APPORTION METHODS- extension to ACTIVITY- element of the project the requires the ratio method time - APPORTION is used when projects MERGE ACTIVITY- has more than one activity closely follow past projects in preceding it features and costs FUNCTION POINT METHODS FOR PARALLEL ACTIVITIES- activities than can take SOFTWARE AND SYSTEM PROJECTS place at the same time FUNCTION POINTS- where PATH- connected, dependent activities software development projects are frequently estimated using weighted CRITICAL PATH- path(s) with the longest macro variables duration through the network LEARNING CURVES- EVENT- used to represent a point in time 2. BOTTOM-UP APPROACHES TEMPLATE METHODS- if the project is BURST ACTIVITY- has more than one activity similar to the past projects immediately following it START-TO-FINISH RELATIONSHIP- the finish of an activity depends on the start of another TWO APPROACHES: activity. 1. ACTIVITY-ON-NODE (AON)- uses node to COMBINATION OF LAG RELATIONSHIP- usually depict an activity; sometimes called start-to-start and finish-to-finish combinations PRECEDENCE DIAGRAM METHOD; tied to two activities. An example—Hammock THREE BASIC RELATIONSHIP THAT MUST BE Activities ESTABLISHED FOR ACTIVITIES INCLUDED IN A HAMMOCK ACTIVITIES - to identify the use of PROJECT NETWORK; fixed resources or costs over a segment of the PREDECESSOR ACTIVITIES-which project. activities must be completed immediately before this activity. SUCCESSOR ACTIVITIES-which activities must immediately follow this activity CONCURRENT OR PARALLEL RELATIONSHIP-which activities can occur while this activity is taking place. 2. ACTIVITY-ON-ARROW (AOR)- uses an arrow to depict activity DETERMINING SLACK OR FLOAT TOTAL SLACK- amount of time an activity can be delayed and not delay the project SENSITIVITY- likelihood the original critical path will change once the project is initiated; function of the number of critical or near-critical paths FREE SLACK (FLOAT)- unique; time an activity can be delayed without delaying any immediately following (successor) activity. PRACTICAL CONSIDERATIONS PROJECT NETWORK TECHNIQUES- have certain logic rules that must be followed CRITICAL PATH - longest path through the network that determines the minimum time required to complete the project. FINISH-TO-START RELATIONSHIP- method for showing relationships among activities in the last section LADDERING- assumption that all immediate preceding activities must be 100 percent complete LAG – minimum amount of time a dependent activity must be delayed to begin or end. START-TO-START RELATIONSHIP- The start of the next activity is delayed until the previous one has started. FINISH-TO-FINISH RELATIONSHIP- The finish of one activity depends on the finish of another activity.