Saab Automobile AB/Chalmers University of Technology. Rogardt Heldal, Tony Heimdahl. Chalmers University of Technology. Tigran Harutyunyan. University of ...
CompSize: Automated Size Estimation of Embedded Software Components Kenneth Lind S bA Saab Automobile t bil AB/Ch AB/Chalmers l U University i it off T Technology h l Rogardt Heldal, Tony Heimdahl Chalmers University of Technology Tigran Harutyunyan University of Gothenburg
Motivation No of computers in highend cars; Ebert, C, Jones, C, ”Embedded Software: F t Figures, Facts, Fi and d Future”, IEEE Computer, Apr. p 2009, pp pp. 42-52 New car prices; US Bureau of Labor Statistics, Statistics Consumer Price Index (http://www.bls.gov/cpi/)
Background ECU
ECU
Communication network 20 – 80 ECUs ECU
Piece cost: 20 – 50 USD Design cost: ~1 MUSD
• Flexibility for future requirements obtained through spare resources like processor capacity and memory space.
Background Too much spare resources => Unnecessary piece cost
Too little spare resources => Premature redesign
Need for decision support!
Background •
•
Memory size in ECU estimated based on requirement specifications and historical data. COSMIC Function Points measured from Component Diagrams and textual requirements.
USERS
BOUNDARY
ENTRIES I/O Hardware OR SOFTWARE OR ENGINEERED DEVICES
EXITS
READS SOFTWARE COMPCOMP ONENT
Storage Hardware WRITES
Black-box
Background
•
Categorization based on factors like (in our domain) – Functionalityy type yp – Quality constraints – Methods & tools Memory size in ECU estimated within 15% accuracy before application software is available.
Experiment data 6000
Software code e size (bytes)
•
5000 Series 1 Series 3 Series 2 Series 4
4000 3000 2000 1000 0 0
20
CFP
40
60
80
Publications This presentation is based on two publications:
•
Lind, K Lind K., Heldal Heldal, R R., Harutyunyan, Harutyunyan T., T and Heimdahl, Heimdahl T.: T: CompSize: Automated Size Estimation of Embedded Software Components, Intl. Workshop on Software Measurement (IWSM), Japan, November 3-4, 3 4, (2011)
•
Lind, K., and Heldal, R.: A Model-Based and Automated Approach to Size Estimation of Embedded Software Components, ACM/IEEE 14th Intl. Conf. on Model Driven Engineering Languages and Systems (MoDELS), New Zealand, ( ) October 16-21,, (2011)
Problem Manual estimation approach Software design & implementation
Domain expert
Architect
Requirement definition
Example p
Decomposition into components
Software engineer Communication definition & implementation
Component Diagram g & Textual Specification
Textual Specification
Example
Identify input for COSMIC Activity
Artifact
Serial data engineer
E Example l
Functional Size measurement
Code Size estimation COSMIC Function Points
Interfaces, Parameters, Categorization
Bytes
Measurement engineer
Requires 2,5 man years in effort for the complete application software in a car!
Problem
• RQ1: “How can UML support pp in modeling g all
information needed for automated estimation of Software Code Size?”
• RQ2: “How much manual effort can be saved by modeling all information needed for automated estimation of Software Code Size?”
Solution Proposed p estimation approach pp Enhanced Component Diagram
Architect
Domain expert
Decomposition p into enhanced components
Requirement definition
Measurement engineer
CompSize
Model-based & automated measurement & estimation Bytes
Textual Specification
Introduced in this work!
Evaluation
RQ1: “How can UML support in modeling all information needed for automated estimation off Software S ft Code C d Size?” Si ?” IInteriorLightStatus_rsp InteriorLightStatus_rsp LGT_ControlTruckBedCargoLamp
5x
CFP=7! USERS
ENTRIES I/O Hardware OR SOFTWARE OR ENGINEERED DEVICES
EXITS
READS SOFTWARE COMPONENT
Storage g Hardware WRITES
Categorization factors functionality = Comf & Conv constraints = no decomposition_level = Distributable granularity_level = Textual spec. …
Direction = in IPickupBedCargoLamp osg IPickupBedCargoLamp_osg PickupBedCargoLamp_osg
BOUNDARY
Variables CARGO LAMP PRESENT:Boolean
Evaluation
IInteriorLightStatus_rsp InteriorLightStatus_rsp LGT_ControlTruckBedCargoLamp
functionality = Comf & Conv constraints = no decomposition_level = Distributable granularity_level = Textual spec. …
Direction = in IPickupBedCargoLamp_osg PickupBedCargoLamp_osg
Variables CARGO LAMP PRESENT:Boolean
Component name
Evaluation
COSMIC data movementt types t
CFP
Categorization factors
Evaluation RQ2: “How How much manual effort can be saved by modeling all information needed for automated estimation of Software Code Size?” Comparison of measurement result
Case study conducted by Master students • Our manual estimations was replicated using the UML Profile
Implemented Co ode Size (Bytes)
2500
2000 R² = 0,99 1500 Author measurement
1000
Student measurement
500
R² = 0,80 0 0
10
20 CFP
30
•
0,5 man years (instead of 2,5!) to estimate the size of the complete application software in a car
Results
• We have defined a UML Profile capturing the • •
information needed for memory size estimation estimation. We have developed a tool that can import the information captured in the UML Profile. Profile Using the UML Profile requires 0,5 man years (instead of 2 2,5 5 man years!) to estimate the size of the complete application software in a car.
Backup
Textual Specification The feature Shall be enabled when the calibration CARGO LAMP PRESENT is set true. If the vehicle p power mode is “OFF”,, and the cargo g lights g are illuminated, the SYSTEM Shall keep the cargo lamps active as long as Inadvertent Load Control power is active. CUSTOMER “ACTION”
INTERIOR ILLUMINATION Lamps Switch On and Vehicle Parked.
CUSTOMER PERCEIVABLE “OUTPUT”
Cargo Lamp Illuminates
MAXIMUM LATENCY “ACTION” to “OUTPUT” 100 ms
Back to Manual Estimation approach
Component Diagram «Interface» I t f
IInteriorLightStatus_rsp «Signal»
InteriorLightStatus_rsp
«use»
«Interface»
IVehicleMovementState_rsp «Signal»
VehicleMovementState_rsp
«use»
«Interface»
IIndvLoadProtectionILS_rsp «Signal»
IndvLoadProtectionILS_rsp
«use»
«Distributable» LGT_ControlTruckBedCargoLamp
«Interface»
IWritePickupBedCargoLamp_osg
Back to Manual Estimation approach
Functional Size Measurement «Interface»
IInteriorLightStatus_rsp «Signal»
InteriorLightStatus_rsp
«use»
«Interface»
IVehicleMovementState_rsp «Signal»
VehicleMovementState_rsp
«use»
«Interface»
IIndvLoadProtectionILS_rsp «Signal»
IndvLoadProtectionILS_rsp
The feature Shall be enabled when the calibration CARGO LAMP PRESENT is set true.
«use»
If the vehicle power mode is “OFF”, and the cargo lights are illuminated, the SYSTEM Shall keep the cargo lamps active as long as Inadvertent Load Control power is active.
«Distributable» LGT_ControlTruckBedCargoLamp _ g p
USERS
BOUNDARY
ENTRIES
«Interface»
IWritePickupBedCargoLamp_osg
CUSTOMER “ACTION”
INTERIOR ILLUMINATION Lamps S it h O Switch On and dV Vehicle hi l Parked.
CUSTOMER PERCEIVABLE “OUTPUT”
Cargo Lamp Illuminates
MAXIMUM LATENCY “ACTION” to “OUTPUT” 100 ms
I/O Hardware OR SOFTWARE OR ENGINEERED DEVICES
EXITS
CFP=7!
READS SOFTWARE COMPONENT
Storage Hardware WRITES
Back to Manual Estimation approach
UML Profile
USERS
ENTRIES
Already in use at Saab
I/O Hardware OR SOFTWARE OR ENGINEERED DEVICES
BOUNDARY
Component
EXITS
CompSizeComponent functionality: String decomposition_level: String granularity_level: String …
p y Property
Back to Proposed Estimation approach
p p y CompSizeProperty
SOFTWARE COMPONENT
Storage Hardware WRITES
Categorization factors
Name of Component
READS
direction in out inout
Components
CompSize
COSMIC data movement types
CFP
Real Code Size
Categorization factors
CompSi e CompSize
Back to Proposed Estimation approach
Estimated Code Size
