Skills for delivering with certainty

Introducing

Function points analysisfor dummies sizing software

How big is this elephant?

Do these guidelines help?

Sizing elephant

seals

Welcome to Function points FP

A little history

Some geography

2.OUTPUT

1.INPUT

3.INQUIRIES

4.INTERNAL FILE

5.EXTERNAL INTERFACE

Transactional

2.OUTPUT

1.INPUT

3.INQUIRIES

4.INTERNAL FILE

5.EXTERNAL INTERFACE

Data Function

Data in motion = Transaction

Data at rest = Storage

How easy is this inquiry?

1124 elementary processes All possible routes Cities converted to 3 char codes international nomenclature Reports

Non stop Hop and reach With wide bodied air craft

Building blocks explained?

Lets learn by a case studySystem : Develop the first Self driving car application ever made

Current state : Appropriate map installed shows only where the car is right now.

To develop : 1. Show us a few possible routes between Office to Airport 2. Inputs : Start point, Destination, 3. Out put - Few possible routes ( Via Station, Bopodi, Camp etc) 4. Complexity : Thousands of possible routes between Office & Airport 5. For instance. 1000s of more or less stupid ones,6. Only a few worth considering. 7. How to let the system choose these last ones? 8. The shortest, and the fastest one? 9. How to let the system count it?10.How to let the car engine be controlled by map, GPS and traffic

Say you do complete wireframing

And.. Compute the different elements

Weightage points for each type

This is how your system points look

This is standard multiplication matrix

To get unadjusted function pointsDo A *B

X

= C (Say)

Multiply like this to get UFC

UFC = Unadjusted Function Point count

This is how C ( Unadjusted Function Count UFC) looks like

We have not yet looked at the

General System Characteristics comprising

Installation ease, Performance,

Distributedness etc

General System Characteristics(GSC) or Total Degree of Influence TDI)

0 (Low) <= GSC value <= 5 (High)

Each can have value 0 to 5

GSC computed

Total Degree of influence ( TDI ) = Sum of all VAFs

0 <= TDI < = 70 VAF can vary in range from 0.65 (when all GSCs are low) to 1.35 (when all GSCs are high).

Applying VAF( Value adjusted Function Points)

VAF = (TDI*0.01) + 0.65For this case TDI or GSC = 44

Therefore VAF = ( 44*0.01) + 0.65 = 0.44+ 0.65 =1.09Easy to see that 0.65< = VAF <= 1.35

( For the GSM project , The Adjusted Function Points)

Adjusted FP Count = Unadjusted FP Count * VAF

In our case :

Unadjusted FP Count = C = 508VAF = 1.09There foreAdjusted FP Count = 508 *1.09 = 553.72

= 554 (say)The project is now of 554 function points

Organization standards needed( Sample values)

= 0.5 person days

= 0.15 ( for <1000 fp project

= Rs 865/=

Organization internal projection ( Sample values)

Parameter

Org standard value/fp

Computed Project value Rounded Value

Outside value

Remarks

Efforts 0.5 Engineerdays

=554*0.5=277 280 310 Say 10 % effort buffer

Quality 0.15 =554*0.15=83.1 90 100 10% quality bufer

Costing 865 =554*865=4,79,210 4,80,000 7,50,000 50% Gross margin

FP/Hour

Project Function Point Size

0

0.05

0.1

0.15

0.2

0.25

0.3

0.35

0 50 100 150 200 250 300 350 400 450

•Every organization has an optimum size /productivity range

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Happy Function pointing @arunpurohit