handout 5

* Property of STI of 28

SE Metrics Basic Measurement

I0065


Estimating

Estimating –Process Overall

Estimating – Step by Step

1 _________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________

* Property of STIPage 3 of 28


I0065

Estimating

Estimate• The approximate measure of size, effort,

duration and staff required to complete a project

Size• The measure of how ‘big’ the product is

Effort• The number of people hours required to

complete an activity

Duration• The number of calendar days from start to

end of an activity

Staff• The number of people applied to an activity

(full or part-time)

3 __________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________



I0065

What is a project and a WBS? Project characteristics

• Has start and end dates• Has set objectives• Uses resources within limits

Work Breakdown Structure• Activities necessary to attain project objectives• Hierarchically structured (often executed

iteratively)• Relates to life cycle

Estimating Principles Invest in the estimate

• Apply correct amount of resources to create and refine the estimate

Understand the options• The estimate of the resources required for a given

scenario cannot be arbitrarily changed Improve the estimate

• Re-estimate often as more information available

Estimating

2 _________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________



I0065

Assumptions• Conditions of the project, environment

or personnel considered true for estimate

Risk• Chance of damage, injury or failure

resulting from estimate Metric

• Quantitative measure of degree of possession of attribute

Requirement• Assertion that must be true for product

to be acceptable to customer Constraint

• Requirement reflecting decision that cannot change

Expectation• Assertion that must be true for product

to achieve complete customer satisfaction

Estimating

4 __________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________



I0065

EstimatePlanning

DetermineProject Size

DevelopProject

Estimates

ReconcileDifferences

AssembleEstimating

Doc.Package

LastScenario?

ReviewEstimate w/Stakeholders

Step 1 Step 2 Step 3 Step 4 Step 5 Step 6

If estimate unacceptable, modify size

No

Estimating – Process Overall

5 _________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________



I0065


7 __________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________



I0065


Six stages with logical grouping of tasks Core process (stages 2, 3, 4 and 5)

iterative Multiple scenarios and techniques Metrics a significant foundation Process is scalable Requires separate definition of

development process (i.e., life cycle)

6 _________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________



I0065


8 __________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________



I0065


9 _________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________



I0065


11 _________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________



I0065


10 ________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________



I0065


Objectives Examine each step in detail Review outputs and purpose of each step Discuss techniques available for each step Perform an activity to illustrate each step

Steps in Estimating Planning

1.1 Examine business opportunity, classify by work type and make preliminary bid/no-bid decision

1.2 Identify person responsible for bid plan

1.3 Create project plan for estimate and bid activity

Estimate Planning - Outputs Bid / no bid decision Preliminary scope, constraints list and plan Selected project manager Estimate plan Support resource requirements

12 _________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________



I0065


Techniques in Estimating Planning

Standard project management approach• Set objectives• Define scope• Assign resources• Estimate effort to produce estimate• Produce schedule• Monitor progress against schedule and effort

estimate

13 ________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________



I0065


Determine Project Size –Outputs

• New or updated requirements document

• New or updated CAR document• Environmental characteristics for

project• Software / documentation size

estimate• Review issues and conclusions

15 _________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________



I0065


Steps in Determining Project Size

2.1 Create / update requirements list to form basis for estimating2.2 Create / update constraints, assumptions and risks (CAR) list2.3 Search project history for similar projects2.4 Estimate size of project (size of software)

2.5 Review estimates of size

14 ________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________



I0065

Techniques in Determining Project Size

Function Point Analysis Lines of Code (LOC) Page of Documentation

Sizing - Function Point Analysis

Component in productivity metric Late 70’s, early 80’s by Allan Albrecht Implementation independent Logical or user perspective Used as metric of comparison in estimating


16 _________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________



I0065


Function Point Analysis

5 Function types• External Input• External Output• External Inquiry• Internal File• External Interface (shared files)

Complexity Project Factors

17 ________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________



I0065


Function Point Analysis - Project Factors 14 different factors Including

• Performance required• Transaction rates• Batch versus on-line split• Assessment of complexity of processing• Needed for multiple sites

Lines of Code Oldest sizing technique Reliant on history or update project Environment (language) dependent Measure of solution not requirement

19 _________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________



I0065

Function Point Analysis -Complexity

FTR• File Types Referenced

RET• Record Element Types

DET• Data Element Types


18 ________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________



I0065


Pages of Documentation Needs standards Needs a commitment to documentation Logically more requirements, more pages Useful in controlled, long term situations Not much experience or history

Steps in Developing Project Estimates3.1 Collect all historical information relevant

to making estimates for this situation3.2 Create estimates for individual WBS

elements (from different people?)3.3 Consolidate (sum?) individual estimates3.4 Prepare data for tool-based estimating3.5 Use tool to produce estimate(s)

20 _________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________



I0065


Develop Project Estimates - Outputs Project history data Estimates for individual WBS elements Consolidated WBS estimate Estimating tool input data Tool-based estimates Estimate reports and analysis results from

tool

21 ________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________



I0065


Bottom-up algorithm for analyze phase Start with understanding activities and

tasks Look at inputs being changed to outputs Establish metrics which impact size of

tasks Create algorithm from metrics Adjust according to environmentActivities in analyze Prepare / plan to analyze Assess current situation Determine detailed functional

requirements Analyze logical system componentsThese depend on say number of users to interview number of inputs/outputs number of events

23 _________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________



I0065

Basic Estimating Techniques (Approaches)

Two basic approaches• Bottom-up

– Task by task with WBS build up– EDS batch and on-line algorithms

• Top down or Algorithmic– Whole project with WBS

breakdown» COCOMO (original or COCOMO

II)» SLiM» SPQR-50/Checkpoint


22 ________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________



I0065


COnstructive COst MOdel Based on deliverable source instructions

(DSI) Mathematical model, 3 versions depending

on organic, semi-detached or embedded classification

Incorporates optimum development time idea

Provides single figure to cover whole project

Use phase breakdown percentages to go lower

SLiM - Software Life Cycle Manager PC-based tool Based on lines of code Model derived from 3000 projects Estimates time, effort, staff, and reliability Considers constraints and environmental

characteristics Used by GM and Technology Architecture

estimating centers

24 _________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________



I0065


Steps in Reconciling Differences4.1 Identify uncertainties and effect on

project4.2 Compare results of different estimating

approaches4.3 Converge estimates based on the results

of the comparison4.4 Determine staff and duration based on

converged estimate and balance to constraints

Reconciling Differences - Outputs Documented project risks Documented differences between

estimates Converged final WBS estimate Constraints, assumptions and risks

document Set of scenario estimates for different

staff, duration and effort combinations

25 ________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________



I0065


Review Estimate with Stakeholders - Steps6.1 Establish costs and prices for each

scenario6.2 Review estimates, costs, and prices for

each scenario to establish viable ones6.3 Select most viable solution(s) and seek

agreement of all involved in solution6.4 Format information for presentation to

stakeholders6.5 Seek agreement and commitment from

stakeholders

Review Estimate with Stakeholders - Outputs Estimate package with costs and prices Estimate comparison worksheet Selection / rejection decisions for each

scenario Agreement of all involved on selected

solution Proposal to customer Estimating package and business

information for project leader Approved proposal

27 _________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________



I0065


Techniques in Reconciling Differences Averaging Weighted averaging Delphi Wideband Delphi

Assemble Estimating Doc. Package - Steps Assemble or update all documentation into

logical package to aid review by, amongst others, the stakeholders

Assemble Estimating Doc. Package - Outputs Documentation package, produced

according to agreed standards

Assemble Estimating Doc. Package -Techniques

Documentation techniques Documentation management

26 ________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________



I0065


Review Estimate with Stakeholders -Techniques

Documentation

Graphical presentation

Facilitated meetings

28 _________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________ ___________________

handout 5

Design