1. PERT REVIEW (last part of Ch 7)

2. Time and Cost Estimation

TODAY

PERT (Program Evaluation and Review Technique)

Not supported by MS Project Gives you probabilities of completion of a

project by a certain time Calculates a standard normal random

variate and uses a probability table to find its probability

PERT INPUTS

A = most optimistic time M = most likely time B = most pessimistic time

PERT formulas

Task mean = (A + 4*M + B)/6 Task Std. Dev. = (B-A)/6 Project mean = sum of all the task means of

tasks on the critical path Project std. Dev = sum of all the task

standard deviations of tasks on the critical path

Where does Estimating occur within PMBOK?

What process group? What knowledge areas? Can you name some of them?

Answers

The planning process group In the Time Management and Cost

Management Knowledge Areas Time Management

– Estimate Activity (Task) Resources– Estimate Activity (Task) Durations

Cost Management– Estimate Costs

Estimation

What are the inputs to these processes? What tools and techniques?

Estimation: An ART

That made McDonnell (of McDonnell/Douglas Aircraft) wealthy

Accurate intelligence information is a help

INPUTS

1. Activity list2. Constraints3. Assumptions4. Resource requirements5. Resource capabilities6. Historical information

TOOLS

1. Expert judgment

2. Historical data3. Analogous estimating4. Simulation

OUTPUTS

1. Activity duration estimates

2. Basis of estimates3. Activity list updates

Tools and Techniques Calibration and Historical Data Individual Expert Judgment Decomposition and Recomposition Estimation by Analogy Proxy-based Estimates Expert Judgment in Groups Software Estimation Tools Use of Multiple Approaches

Estimation Methodologies

Most firms have their own methodology Standard Procedures Once again, what do we estimate?

– Resources– Time– Cost

The Cost estimation Story—Steve McConnell

You can’t tell exactly what its going to cost

until you know exactly what IT is.

(Which is why we spent so much time

talking about thorough product conceptualization and definition)

Differentiate Estimates from Targets and Commitments

“We will have it done in three months” “Why three months???” “Because that is when the trade show

happens…”

Is it better to overestimate or under estimate

Effect Cost

Schedule

100%<100% >100%

Underestimation Overestimation

Target as a Percentage of Nominal Estimate

A Rule of Thumb

The time to design, document and code a module =

equals the time to debug it (TEST IT)

According to Gildersleeve

Estimating Rules (Rakos) Never use inexperienced persons to estimate Get group estimates if possible Never force an estimate on a programmer Never take an average of different estimates Granularize down to FOUR or less weeks, roughly Always add for contingency Always quote a range when giving estimates

Rakos’ Conclusions to Estimating

Our weakest talent Estimating is iterative Estimating is still an art

Review: Project Time Management Processes

Project time management involves the processes required to ensure timely completion of a project. Processes include:– Define activities– Sequence activities

– Estimate Activity resources– Estimate Activity durations– Develop Schedule– Control Schedule

Which of these gets performed in the Planning and Budgeting Stage??

A Typical Task Duration Process

Assign the task to a project player Ask the player how long it will take him or her to

complete the task (This gives the player ownership in the planning)

Player provides their best estimate The player understands that they will be required

to complete the task within their estimate—their feet will be “held to the fire”

Time Estimation: Goldratt

Claims team players add safety to their estimates

What is safety?? Can determine how much by asking the

question, “How sure are you that you will finish your task in the time you allotted?”

Time Estimation--programmers

Naïve programmers have a horrible reputation for underestimating task durations and costs

Time Estimation—making time for creativity: SLACK

Keep in mind that customers unintentionally put projects under extraordinary schedule pressure—more for less

A consideration in schedule development is to take the tasks requiring creativity and place them on ____?!?

Needed: A Rule-based Expert System for adjusting individual

task durations IF ESTIMATER IS SEASONED

(EXPERIENCED) AND IF THE WORK PACKAGE REQUIRES CREATIVITY ON THE PART OF THE ESTIMATOR, THEN LEAVE ESTIMATE AS IS.

IF ESTIMATER IS NOT SEASONED AND ESTIMATE APPEARS TO BE OPTIMISTIC, THEN INCREASE ESTIMATE BY 30%.

ANOTHER AI RULE

IF ESTIMATOR IS SEASONED AND ESTIMATOR ASSERTS 90% OR ABOVE CONFIDENCE HE WILL COMPLETE WORK WITHIN HIS ESTIMATE AND IF WORK PACKAGE DOES NOT REQUIRE SIGNIFICANT CREATIVITY, REDUCE ESTIMATE BY 40% -- 50%

Time Estimation

What are the three approaches to time estimation??– Expert judgment– History database– Computer model or formula

Project Cost Management Processes Plan Cost Management Estimate Costs: developing an estimate of

the costs and resources needed to complete a project

Determine Budget: allocating the overall cost estimate to individual work items to establish a baseline for measuring performance

Control Costs: controlling changes to the project budget

Cost Estimating

We need to speak the language and understand the terminology:ROI, IRR, NPV, Sunk costsTangible and intangible costsDirect and indirect costsLearning curve theoryReserves ($ included in a cost estimate to

mitigate cost risk; also called contingency reserves)

Cost Estimating

An important output of project cost management is a cost estimate

There are several types of cost estimates and tools and techniques to help create them

It is also important to develop a cost management plan that describes how cost variances will be managed on the project

Proposal Pricing Strategies--Kerzner

Type I Acquisition: One of a kind project with little or no follow-on opportunity

» win the project, perform well and make a profit

Type II Acquisition: New Program with potential for large follow-on business or representing a desired surge into a new market

» win the project, perform well and gain a foothold in a new market segment, usually at a loss

Table 6-2. Types of Cost Estimates

Type of Estimate When Done Why Done How Accurate

Rough Order of Magnitude (ROM) WAG SWAG

Very early in the project life cycle, often 3–5 years before project completion

Provides rough ballpark of cost for selection decisions

–25%, +75%

Budgetary Early, 1–2 years out Puts dollars in the budget plans

–10%, +25%

Definitive Later in the project, < 1 year out

Provides details for purchases, estimate actual costs

–5%, +10%

Estimation in General—COST or TIME

History data base Expert judgement a model like COCOMO

Cost Estimation Tools and Techniques 4 basic tools and techniques for cost estimates

(Schwalbe—Ch 6):– Analogous or top-down: use the actual cost of a previous,

similar project as the basis for the new estimate

– Bottom-up: estimate individual work items and sum them to get a total estimate

– Parametric: use project characteristics in a mathematical model to estimate costs

– Computerized tools: use spreadsheets, project management software, or other software to help estimate costs

Constructive Cost Model (COCOMO)

Barry Boehm helped develop the COCOMO models for estimating software development costs

Parameters include source lines of code or function points

COCOMO II is a computerized model available on the web

Boehm suggests that only parametric models do not suffer from the limits of human decision-making

Stop here—will not test you on anything else

Lefkon’s Methodology

1.  Divide the software project into as many individual steps/tasks/modules as possible.2. Predict the level of effort required to complete each task and multiply that prediction by 2. 3.  Add up the numbers and multiply by 2.0 again to account for testing and debugging.4.  Take the total and multiply by 1.25 to account for meetings, administration, and paperwork.5. Multiply this level of effort by your company’s “magic number” for labor costs. 

Lefkon’s Methodology

6. Present this to management as a range. Take the cost as predicted above and present the range as –10 percent and +25 percent.

7.  Stand your ground and remind management that you did not arbitrarily come up with these numbers and they cannot be adjusted arbitrarily. You may have to suggest reducing scope and cost if management does not agree with your estimate.

8. Revise your project budget as you undertake and complete the project.

Typical Problems with IT Cost Estimates

Developing an estimate for a large software project is a complex task requiring a significant amount of effort. Remember that estimates are done at various stages of the project

Many people doing estimates have little experience doing them. Try to provide training and mentoring.

IT People have a bias toward underestimation. Review estimates and ask important questions to make sure estimates are not biased

Management wants a number for a bid, not a real estimate. Project managers must negotiate with project sponsors to create realistic cost estimates

Table 6-3. Business Systems Replacement Project Cost Estimate Overview

Category DescriptionObjective Install a suite of packaged financial applications

software which will enable more timelyinformation for management decision-making,easier access to data by the ultimate end user, andallow for cost savings through productivityimprovements throughout the company.

Scope The core financial systems will be replaced byOracle financial applications. These systemsinclude:

General Ledger Fixed Assets Ops Report [AU: spell out Ops] Accounts Payable Accounts Receivable Project Accounting Project Management

Assumptions Oracle's software provides

Minimal customization No change in procurement systems during

accounts payable implementationCost/Benefit Analysis& Internal Rate of Return (IRR)

BSR was broken down into a three-year cashoutlay without depreciation. Costs arerepresented in thousands. Capital and expensesare combined in this example.

Table 6-4. Business Systems Replacement Project Cash Flow Analysis

FY95

($000)

FY96

($000)

FY97

($000)

3 YearTotal($000)

Future AnnualCosts/Savings

($000)CostsOracle/PM Software(List Price)

992 500 0 1492 0

60% Discount (595) (595)Oracle Credits (397) 0 (397)

Net Cash for Software 0 500 500Software Maintenance 0 90 250 340 250Hardware & Maintenance 0 270 270 540 270Consulting &Training 205 320 0 525 0Tax & Acquisition 0 150 80 230 50Total Purchased Costs 205 1330 600 2135 570Information Services &Technology (IS&T)

500 1850 1200 3550 0

Finance/Other Staff 200 990 580 1770Total Costs 905 4170 2380 7455 570

SavingsMainframe (101) (483) (584) (597)Finance/Asset/PM (160) (1160) (1320) (2320)IS&T Support/Data Entry (88) (384) (472) (800)Interest 0 (25) (25) (103)Total Savings (349) (2052) (2401) (3820)

Net Cost (Savings) 905 3821 328 5054 (3250)

8 Year InternalRate of Return

35%

Cost Budgeting Cost budget involves allocating the project

cost estimate to individual work items and providing a cost baseline

For example, in the Business Systems Replacement project, there was a total purchased costs estimate for FY97 of $600,000 and another $1.2 million for Information Services and Technology

These amounts were allocated to appropriate budgets as shown in Table 6-5

Table 6-5. Business Systems Replacement Project Budget Estimates for FY97 and Explanations

Budget Category Estimated Costs ExplanationHeadcount (FTE) 13 Included are 9 programmer/analysts, 2

database analysts, 2 infrastructuretechnicians.

Compensation $1,008,500 Calculated by employee change notices(ECNs) and assumed a 4% pay increase inJune. Overload support was planned at$10,000.

Consultant/PurchasedServices

$424,500 Expected consulting needs in support of theProject Accounting and Cascadeimplementation efforts; maintenanceexpenses associated with the Hewlett-Packard (HP) computing platforms;maintenance expenses associated with thesoftware purchased in support of the BSRproject.

Travel $25,000 Incidental travel expenses incurred insupport of the BSR project, most associatedwith attendance of user conferences andoff-site training.

Depreciation $91,000 Included is the per head share ofworkstation depreciation, the Cascade HPplatform depreciation, and the depreciationexpense associated with capitalizedsoftware purchases.

Rents/Leases $98,000 Expenses associated with the Mach1computing platforms.

Other Suppliesand Expenses

$153,000 Incidental expenses associated with thingssuch as training, reward and recognition,long distance phone charges, miscellaneousoffice supplies.

Total Costs $1,800,000

Designing the Baseline One of the most crucial inputs to the pricing

decision Baseline design should be started early so its cost

estimates can be included in the proposal Effective pricing should begin a long time before

proposal development– Gives management an opportunity to terminate a bid

initiative before too many resources get committed to proposal development, presentations, negotiations, etc..

Pricing Process This activity schedules the development of

the work breakdown structure and provides management with two of the three operational tools necessary for the control of a system or project

The third tool is the WBS

The WBS as price estimating tool Provides the basis for effective and open

communication between functional management and program/project management

After pricing is complete the WBS forms the basis of a communications tool by documenting the performance agreed on in the pricing effort.

Organizational Input Requirements

After the WBS and activity schedules are established, an organizational meeting is called.– The WBS is described in depth– Responsibilities are clarified– Costing information is solicited and collected from the

responsible parties A short time fuse is usually involved in

estimating/pricing which makes it all the more risky – RFP’s sometimes require a response within 30 days of

their submittal

Labor Distributions Functional units supply their input in the form of

man-hours» See Figure 14-2

Man-hours submitted are often over-estimated Man-hours are converted to dollars by multiplying

by the labor rates Rates are only averages Base rates are then escalated as a % factor, based

on past experience

Labor Distributions--Conflict Resolution

The reduction of man-hours is often the source of heated discussions between project and functional management

Most common solution rests with the project or program manager

This becomes the usual turf-fight How would you resolve all such

conflicts???

A Proposal Manager Integrates the activities of the program and

functional managers Insures that a robust proposal gets

submitted to the REQUESTER on time

Overhead Rates Program/project costs involve both direct labor

and indirect (OVERHEAD) costs Each team member should understand overhead

rates If overhead rates are more than 50% of direct

regular time and not chargeable to overtime, then overtime at 150% regular time may be cheaper

Overhead rates in manufacturing can be 300-450%

Elements of Overhead Rates (Indirect Costs)

Building maintenance Building rent Cafeteria Clerical Consulting Corporate Salaries Depreciation of equip. Executive Salaries

Group insurance Holidays Moving/storage exp. Personnel recruitment Retirement plans Sick leave Telephone/Utilities Vacation

Why are Overhead Rates of Interest to Project Management???

These rates must be included in any project cost calculation!!!

The contractor is going to pay both your direct and your indirect overhead costs if yours is the winning bid

Where do the costs associated with bidding and proposing go? Does anybody pay for them or are they just a SUNK cost???

Let’s REVIEW: What are the Major Cost Components?

Salary structure Overhead structure Labor hours required Cost of materials and support

Cost of Materials?? Required Software Diet coke, pizza

Materials Support Costs Are submitted by month for each month of

the project An escalation factor for material costs must

be applied

Pricing out the Work—STEPS (from Kerzner, p. 738)

Provide a complete definition of the work requirements

Establish a logic network with checkpoints Develop the work breakdown structure Price out the WBS

Pricing out the Work--STEPS, Cont’d

Review WBS costs with each functional manager

Decide on the basic course of action Establish reasonable costs for each WBS

element Review the base case costs with upper-level

management

Pricing out the Work--STEPS, Cont’d

Negotiate with functional managers for qualified personnel

Develop the linear responsibility chart Develop the final detailed and PERT/CPM

schedules Establish pricing cost summary reports Document the result in a project plan

Smoothing out Department Man-hours

Ramp-up at project initiation and Ramp-down at project completion cause step functions in manpower requirements, as shown in Figure 14-8

Functional managers attempt to SMOOTH this out QUESTION?? Does the department have

sufficient resources to fulfill the requirements?

Smoothing out Department Man-hours

ANOTHER QUESTION?? Can the departments ramp-up fast enough?

The Pricing Review Procedure Based on Kerzner’s work Remember only 30 days to get the proposal

out and this is one of 13 steps Many contractors require the actual team

members to be identified in the proposal What solution comes to mind?

Systems Pricing The project pricing model (also called the

strategic planning model) acts as a management information system

Also provides management with an invaluable tool for performing perturbation analysis on the base case costs

Developing the Supporting/Backup Costs

Some proposals require backup support When required backup support must be

included in the pricing An issue is the type of contract

Types of contracts Fixed-price (developer assumes all of the

risk) Cost-plus (contractor pays for every hour

invested and thus assumes all the risk) An infinite array in between these

The Low-Bidder Dilemma The price of your contract will definitely

affect the viability of your proposal A low price on cost-plus type proposals is

suspect A low price on fixed-price contracts may be

perceived as impossible and undoable, or if accepted will lead to a disaster

The Price on the Proposal is always relative to:

the competitive prices the customer budget the bidder’s cost estimate IN ANY CASE, LOW PRICING

WITHOUT MARKET INFORMATION IS MEANINGLESS

If its a new market for the Developer:

Cost sharing may be an effective strategy Bidding below your actual costs is

commonplace Contractor’s objectives might include

system life cycle cost or unit production cost

The Bottom Line on Price THE LOWEST BIDDER IS NOT

NECESSARILY THE AUTOMATIC WINNER– Makes project a risky image regarding cost,

performance or schedule The ability to perform under contract is a definite

consideration A compliant, technically and managerially sound

proposal based on past experience, with realistic, well-documented cost figures, is often chosen over the lowest bidder

Special Problems• Pricing must include an understanding of cost control--

how costs are billed back to the project

• There are three situations:

– Work is priced out at the department average, and all work performed is charged to the project at the department average, regardless of who performed the work

– Work is priced out at the dept.. average, but all work performed is billed back to the project at the actual salary of the employees who performed the work

– Work is priced out at the actual salary of those employees who will perform the work, and the cost is billed back the same way.

» This is the ideal situation

This is as far as we will go with these slides—ignore the

remainder

Estimating Pitfalls• The “buy-in” decision is the most serious pitfall

because it means that the project will be under-funded

• If the customer initially defines the requirements and you (the developer) further refine them and the customer doesn’t understand what you’ve done, whose fault is it?

Estimating High-Risk Projects• Validity of historical estimates determine the

difference between high-risk and low-risk projects

• Estimating high-risk projects is commonly done by means of the rolling wave or moving window approach– For a 12-month project the first six months are

estimated to level 5, while the last six months are estimated to level two only.

– As the project proceeds more and more of the last six months is estimated to level 5

– See Figure 14-13, Kerzner

Project Risks RISKS--Factors that increase the

probability that the project’s goals of time, cost and performance will not be met

• See Figures 14-14, 14-15 and Table 14-13 (Especially useful)

Common Risks include: Poorly defined requirements Lack of qualified resources Lack of management support Poor estimating Inexperienced project manager

Tools to Aid in Risk Identification

Decision Support Systems Expected value measures Trend analysis/projection Independent reviews and audits

Six steps to risk management are: Identification of the risk Quantification of the risk Prioritizing the risk Developing a strategy for managing the risk

– A contingency plan Project sponsor/executive review Taking action

The Disaster of Applying the 10 % Solution to Project Estimates

10% is taken from every on-going project to create a budget out of thin air

The result is havoc on top of chaos Most high-level executive committees do not

realize the impact of adopting the 10% solution A REDUCTION IN BUDGET MUST BE

ACCOMPANIED BY A TRADEOFF IN TIME OR PERFORMANCE

The Disaster of the 10% Solution, Cont’d

90% of the budget generates 10% of the desired service or performance levels and the remaining 10% will generate the last 90% of the desired service or performance

If there is FAT, i.e., padding, it may, however, be possible to sustain a cut in the project budget without major consequence– Most projects do not have FAT

Cost vs. Performance I much prefer the word performance to

quality here A 10% reduction in cost can be expected to

produce much greater than a 10% reduction in performance

More on the 10% Solution 10% reduction solutions should be

undertaken only after a careful impact study has been completed

A far better choice is for the executive committee to cancel or de-scope some projects in order to release funds

14.19 Life-Cycle Costing (LCC) These are the total costs to the organization

for the ownership and acquisition of a product over its full life

Especially appropriate for in-house software development projects, but is used in some (outhouse) contracted projects as well

Life-cycle cost breakdown R & D Costs (Definition, Analysis) Production cost (Design) Construction cost (Programming and

testing) Operation and maintenance cost Product retirement cost

Life-cycle costing process Define the problem Define the requirements of the cost model

being used Collect historical data-cost relationships Develop estimates and test results

Successful applications of LCC will:

Provide downstream resource impact visibility

Provide life-cycle cost management Influence R&D decision making Support downstream strategic budgeting

Estimating Methods for LCC Method choice is based on the problem context,

operational considerations, etc. Informal estimating methods

– Judgment based on experience– Analogy– SWAG method, ROM method– Rule-of-thumb method

Formal estimating methods– Detailed (from industrial engineering standards)– Parametric

Figure 14-18 For every $12 DOD puts into R&D, $28 are

needed downstream for production and $60 for operation and support

After Conceptual definition and demonstration/validation, 85% of the lifecycle decisions are made and cost reduction opportunities are down to 22%

14.20 Logistics Support A frequent occurrence in software development

where the developer is paid to provide after-market support in the form of operation and maintenance on the product (deliverable)

Recall that after the design phase 85% of the deliverable’s life-cycle cost has been committed and the majority of the total life-cycle cost is still ahead >> 60%

Performance metrics for Products requiring Logistics Support

Suppportability--the ability to maintain or acquire the necessary human resources to support the system

Readiness--measure of how good we are at keeping the product performing as planned and how quickly we can make repairs during a shutdown

Ten elements of logistics support Maintenance planning Manpower and

personnel Supply support Support equipment Technical data See page 765

Training and training support

Computer resources support

Facilities Packaging,

handling, storage and transportation

Design interface

Estimating --

An iterative process– Definition, Analysis, Design

After Definition, 50-100% off After Analysis, 25-50% off After Medium level design--within 10% A good WBS is absolutely essential to do

estimating

Estimating Techniques

Professional Judgment Developer estimate History (database) Formulas

Use of Professional Judgment Based on WBS, an expert judgment

estimate is made for each work package Amazingly accurate when experts are

available Often, however experts aren’t available

Developer Estimate

The programmer assigned to the work package will make every effort to complete the task in the time he estimated it would take

Use of History Database

For this to work, your firm must keep a history database

The database should record how long each task took and who did the task

Break new projects up into tasks that have a history database

8 to 1 productivity ratio between best to worst professional

Questions, Cont’d

How much of the total time does Brooks devote to Definition, Analysis and Design?

1/3

How much time to coding? 1/6 to Coding

How much time to testing? 1/4 to component test and early system test 1/4 to total system test

So how much time are you going to devote to testing in your projects?????

Use of Formulas

COCOMO--project cost, effort, schedule, staffing for each of the phases:– Preliminary design– Detailed design– Code and unit test– System test

COCOMO was developed by Barry Boehm in 1981--COnstructive COst MOdel

Inputs to COCOMO

Monthly cost of staff involved Factors indicating the general level of

complexity of the software Programming practices and tools used Experience of staff Lines of LOSC--rendering COCOMO

unusable

Function Points

A user input User display Peripheral I/O Restructuring data Condition checking Calculation Branching

Function point approach--BEFORE YOU LEAP

Vendor is Gordon Group It must know how many LOSC are required

for each function point. It calculates LOSC based on function points

it knows about and feeds this into the COCOMO algorithm

Estimacs from CA (Computer Associates)

Can take into account modern code generation tools

Determines effort, but also – Hardware required– financial break-even analysis– risk analysis– maintenance costs

Expensive > $20K

Estimating Programming: Function Points

D = C * ( G + J) D is the task duration in person-days C is the complexity of the task G is the assigned persons’ general

experience J is the assigned professional’s job

knowledge factor

Complexity Must break task down into its smallest possible

repeatable functions Then add up the complexity of each function User input, user display, peripheral I/O,

restructuring data, condition checking, calculation, etc.

Repeatable functions are called function points. Function points are graded as SIMPLE, COMPLEX and VERY COMPLEX

Productivity

Your average programmer gets a productivity factor of 1 for G

Slower programmers get factors > 1 Faster programmers get factors < 1

Formula method conclusions

Will work if you develop accurate factors Can be used for any task from building a

house to developing software Depends on how well you granularize

Estimating The Analysis Phase

Interviews Analyze Existing Documents and Systems Prepare Functional Specification Presentation

RATIOS

PHASE PERCENTAGE Definition phase -- 10% Analysis phase -- 20% Design phase -- 10% Programming -- 20% System test -- 17% Acceptance -- 7% Operation -- 16%

This breaks down to:

PLAN -- 40% BUILD -- 20% TEST -- 40%

Another Rule of Thumb

The time to design, document and code a module =

equals the time to debug it

According to Gildersleeve

Can you use RATIOS for Forecasting?

Suppose you found that it took 20 days to do definition.

How long, based on ratios will it take to do the project?

Estimating Rules Never use inexperienced persons to estimate Get group estimates if possible Never force an estimate on a programmer Never take an average of different estimates Granularize down to one week or less Always add for contingency Always quote a range when giving estimates

Conclusions to Estimating

Our weakest talent Estimating is iterative Estimating is still an art

Scheduling --

Also assists with estimating, especially when PM software is used

PM software supports

WBS Gantt PERT Calendar(s) Resources and their assignments

PERT

Use activity on node approach– doesn’t require dummy activities

Understand what float is--it is slack Critical path is the longest path shows precedent activities, relationships doesn’t show what will be done when, by

whom

Resource allocation

Assign tasks to individuals whose skill level suits the task

Assign similar tasks to the same person Assign time-critical tasks to your most reliable

people Assign tasks that communicate to the same

individual to minimize people’s interaction Don’t assign too many different tasks to any one

individual

Reducing task duration by adding manpower

Add 20% direct time for each additional member on a professional team

If it takes 10 person days for one person, it will take 12 person days for two people, 14.4 person days for three people, etc.

Cost effects of adding resources

More resources, gets the project done sooner, USUALLY

But it also costs more The PM must come up with the best

balance, depending on the priorities set by management or the user

Shortening the duration of projects

Fast tracking Crashing

– Adding resources to the critical path– Allowing your current CP teams members to

work overtime

Crashing projects

Crash tasks on the critical path only, only as long as no other path becomes critical

If other paths become critical, the analyst must crash those as well

Gantt Chart

a time bar chart Invented by Henry Gantt in 1910 Determine the units of time Mark all known calendar events at bottom Schedule each activity from PERT

Use three sets of Gantt’s

one for yourself alone, with all float and contingency visible

second for the individuals involved--their resource Gantt, contingencies hidden

third for distribution to upper management--contingencies hidden

Include a 10% contingency into all estimates

Conclusions to Scheduling

Use PM software--worth every penny Do at least one PERT and one GANTT

manually, just to get a feel for the process

Recitation

What is the probability of completing a project by its estimated completion time??

What is the formula for calculating the completion time for a PERT network?

What is the formula for calculating the standard deviation of the completion time for a PERT network?

Name some processes that are part of project integration management