Download presentation
Presentation is loading. Please wait.
Published byMerilyn McKinney Modified over 9 years ago
1
Department of Informatics, UC Irvine SDCL Collaboration Laboratory Software Design and sdcl.ics.uci.edu 1 Informatics 43 Introduction to Software Engineering Lecture 10-1 December 9, 2014 Emily Navarro Duplication of course material for any commercial purpose without the explicit written permission of the professor is prohibited.
2
Department of Informatics, UC Irvine SDCL Collaboration Laboratory Software Design and sdcl.ics.uci.edu 2 Today’s Lecture Announcements Moore’s Law Project estimation Test 2 Wrap-up
3
Department of Informatics, UC Irvine SDCL Collaboration Laboratory Software Design and sdcl.ics.uci.edu 3 Today’s Lecture Announcements Moore’s Law Project estimation Test 2 Wrap-up
4
Department of Informatics, UC Irvine SDCL Collaboration Laboratory Software Design and sdcl.ics.uci.edu 4 Some Announcements 0.5% extra credit for submitting the EEE Course Evaluation I will be in my office on Thursday, December 18 3:30-5:30pm for pickup of Test 2, HW 3, HW 2, Quiz 6, etc.
5
Department of Informatics, UC Irvine SDCL Collaboration Laboratory Software Design and sdcl.ics.uci.edu 5 Today’s Lecture Announcements Moore’s Law Project estimation Test 2 Wrap-up
6
Department of Informatics, UC Irvine SDCL Collaboration Laboratory Software Design and sdcl.ics.uci.edu 6 Moore’s Law The number of transistors on integrated circuits doubles approximately every two years. 6 Intel P4004 from 1969 2,300 transistors, 108 kHz clock speed Intel Core i7 from 2010 731,000,000 transistors, 3.06 GHz clock speed
7
Department of Informatics, UC Irvine SDCL Collaboration Laboratory Software Design and sdcl.ics.uci.edu 7 Moore’s Law Electronics 19 April 1965
8
Department of Informatics, UC Irvine SDCL Collaboration Laboratory Software Design and sdcl.ics.uci.edu 8 Moore’s Original Data Gordon Moore Electronics 19 April 1965
9
Department of Informatics, UC Irvine SDCL Collaboration Laboratory Software Design and sdcl.ics.uci.edu 9 9 Moore’s Law to 2000
10
Department of Informatics, UC Irvine SDCL Collaboration Laboratory Software Design and sdcl.ics.uci.edu 10 Moore’s Law through 2010 10 Motorola Intel
11
Department of Informatics, UC Irvine SDCL Collaboration Laboratory Software Design and sdcl.ics.uci.edu 11 Moore’s Law with MS OS
12
Department of Informatics, UC Irvine SDCL Collaboration Laboratory Software Design and sdcl.ics.uci.edu 12 Moore’s Law in the Future?
13
Department of Informatics, UC Irvine SDCL Collaboration Laboratory Software Design and sdcl.ics.uci.edu 13 Moore’s Law Has held true for almost 50 years Is so “true” that it guides the semiconductor industry in long- term planning and setting targets for research and development May have reached its last stages with chips shrinking to the atomic level – But Intel claims they will continue to follow Moore’s Law
14
Department of Informatics, UC Irvine SDCL Collaboration Laboratory Software Design and sdcl.ics.uci.edu 14 Today’s Lecture Announcements Moore’s Law Project estimation Test 2 Wrap-up
15
Department of Informatics, UC Irvine SDCL Collaboration Laboratory Software Design and sdcl.ics.uci.edu 15 Project Estimation – Why? We need to be able to estimate things like how long a project will take, how many people are needed, how much it will cost, etc. For the purpose of planning, giving bids, etc.
16
Department of Informatics, UC Irvine SDCL Collaboration Laboratory Software Design and sdcl.ics.uci.edu 16 What to estimate Effort (person-months) Duration (calendar months) Cost (dollars) KLOC (thousands of lines of code)
17
Department of Informatics, UC Irvine SDCL Collaboration Laboratory Software Design and sdcl.ics.uci.edu 17 Estimating a project Approach 1: Naïve estimation – Take your best guess Approach 2: Estimation by parts – Bottom-up or top-down, depending on where you start Approach 3: Re-estimation – As more time is spent on a project, uncertainty decreases
18
Department of Informatics, UC Irvine SDCL Collaboration Laboratory Software Design and sdcl.ics.uci.edu 18 Longhorn Project (2003) – 16 MLOC, 5000 people, 3 years – 1067 LOC/person/year Grady and Caswell at HP (1987) – ~1100 LOC/person/year Brooks (1975) IBM OS/360 – 600-800 instructions/person/year in control group Productivity Rates
19
Department of Informatics, UC Irvine SDCL Collaboration Laboratory Software Design and sdcl.ics.uci.edu 19 Factors Affecting Productivity Rates Application domain experience Process quality Project size – Negative relationship Technology support Working environment
20
Department of Informatics, UC Irvine SDCL Collaboration Laboratory Software Design and sdcl.ics.uci.edu 20 A general estimation formula Textbook, p. 275: Units of effort = a + b(size) c + ACCUM(factors) a = base cost b = scales the size variable, derived from past projects c = allows estimated project size to influence the effort estimation non-linearly ACCUM = a function, sum or product or ? factors = other influences on the effort
21
Department of Informatics, UC Irvine SDCL Collaboration Laboratory Software Design and sdcl.ics.uci.edu 21 COCOMO - A Specific Estimation Model (Boehm) One of the most widely used software estimation models Predicts effort and schedule based on inputs relating to the size of the software and a number of cost drivers that affect productivity Steps 1.Determine project mode (organic/simple, semidetached/intermediate, embedded/difficult) 2.Estimate the size of project (in KLOC or function points) 3.Review 15 factors (cost-drivers), and estimate the impact of each on the project 4.Determine project effort by inserting the estimated values into an effort formula
22
Department of Informatics, UC Irvine SDCL Collaboration Laboratory Software Design and sdcl.ics.uci.edu 22 COCOMO Project Modes Project mode is based on 8 parameters – The team’s understanding of project objectives – The team’s experience with similar projects – The project’s need to conform with established requirements – The project’s need to conform with established external interfaces – The need to develop the project concurrently with new systems/operational procedures – The project’s need for new technology, architecture, etc. – The project’s need to meet or beat the schedule – Project size
23
Department of Informatics, UC Irvine SDCL Collaboration Laboratory Software Design and sdcl.ics.uci.edu 23 COCOMO Project Modes Organic Mode – Small teams with good experience working with “less than rigid” requirements Semidetached Mode – Medium teams with mixed experience working with a mixture of rigid and less than rigid requirements Embedded Mode – Projects that must be developed within a series of tight constraints Each mode has its own effort estimation formula
24
Department of Informatics, UC Irvine SDCL Collaboration Laboratory Software Design and sdcl.ics.uci.edu 24 COCOMO Cost Drivers Product attributes – Required software reliability – Database size – Product complexity Computer attributes – Execution time constraint – Main memory constraint – Virtual machine complexity – Computer turnaround time Personnel attributes – Analyst capability – Applications experience – Programmer capability – Virtual machine experience – Programming language experience Project attributes – Use of modern practice – Use of software tools – Required development schedule
25
Department of Informatics, UC Irvine SDCL Collaboration Laboratory Software Design and sdcl.ics.uci.edu 25 Comparison of Formulas HalsteadBoehmWalston-Felix KLOCE=0.7 KLOC 1.50 E=2.4 KLOC 1.05 E=5.2 KLOC 0.91 1 10 50 100 1000 0.7 22.1 247.5 700.0 22,135.9 2.4 26.9 145.9 302.1 3,390.1 5.2 42.3 182.8 343.6 2,792.6 Coefficients derived using actual project data – Variability in project characteristics?
26
Department of Informatics, UC Irvine SDCL Collaboration Laboratory Software Design and sdcl.ics.uci.edu 26 What to Measure/Estimate Lines of code – e.g. delivered lines of executable source code Function points – count inputs, outputs, files Feature points – similar to function points, also count algorithms Object points – count screens, reports, and 3-GL components
27
Department of Informatics, UC Irvine SDCL Collaboration Laboratory Software Design and sdcl.ics.uci.edu 27 Function Points Analyze specifications and high-level design for – External inputs – External outputs – External inquiries – Internal logical files (e.g. classes, data structures) – External interface files The result (after plugging them into a formula) is a number of Function Points. Maybe: person-months = 0.20 * FP 1.5
28
Department of Informatics, UC Irvine SDCL Collaboration Laboratory Software Design and sdcl.ics.uci.edu 28 Today’s Lecture Announcements Moore’s Law Project estimation Test 2 Wrap-up
29
Department of Informatics, UC Irvine SDCL Collaboration Laboratory Software Design and sdcl.ics.uci.edu 29 Test 2 Items from Today’s Lecture Moore’s Law Project estimation – Factors affecting productivity rates – COCOMO (know what it is) – Function points
30
Department of Informatics, UC Irvine SDCL Collaboration Laboratory Software Design and sdcl.ics.uci.edu 30 Today’s Lecture Announcements Moore’s Law Project estimation Test 2 Wrap-up
31
Department of Informatics, UC Irvine SDCL Collaboration Laboratory Software Design and sdcl.ics.uci.edu 31 What Did We Learn? What is software engineering? – Perspectives – Definitions – Essential qualities (complexity, conformity, changeability, invisibility) Software engineering principles – Rigor and formality – Separation of concerns modularity divide and conquer abstraction – Anticipation of change – Generality – Incrementality Software failures/fiascos – Many related to requirements
32
Department of Informatics, UC Irvine SDCL Collaboration Laboratory Software Design and sdcl.ics.uci.edu 32 What Did We Learn? Requirements Engineering – Requirements document (Homework 1) Mythical Man Month Use cases Software architecture Software process models Version control – Git (Homework 2) Designs, models, notations User orientation Testing Moore’s law Project estimation
33
Department of Informatics, UC Irvine SDCL Collaboration Laboratory Software Design and sdcl.ics.uci.edu 33 What is Software Engineering? Software – Engineering -
34
Department of Informatics, UC Irvine SDCL Collaboration Laboratory Software Design and sdcl.ics.uci.edu 34 What is Software Engineering? Software – Engineering - Code Documentation, user manuals Designs, specifications Test cases Plans and schedules
35
Department of Informatics, UC Irvine SDCL Collaboration Laboratory Software Design and sdcl.ics.uci.edu 35 What is Software Engineering? Software – Engineering - Code Documentation, user manuals Designs, specifications Test cases Plans and schedules Skill and knowledge Application of scientific principles Trade-offs, cost / benefit analysis
36
Department of Informatics, UC Irvine SDCL Collaboration Laboratory Software Design and sdcl.ics.uci.edu 36 Software engineering “A broad field that touches upon all aspects of developing and supporting a software system.” [Tsui, Karam, Bernal]
37
Department of Informatics, UC Irvine SDCL Collaboration Laboratory Software Design and sdcl.ics.uci.edu 37 Software engineering “A broad field that touches upon all aspects of developing and supporting a software system.” [Tsui, Karam, Bernal]
38
Department of Informatics, UC Irvine SDCL Collaboration Laboratory Software Design and sdcl.ics.uci.edu 38 Software engineering “A discipline that deals with the building of software systems which are so large that they are built by a team or teams of engineers.” [Ghezzi, Jazayeri, Mandrioli]
39
Department of Informatics, UC Irvine SDCL Collaboration Laboratory Software Design and sdcl.ics.uci.edu 39 Software engineering “A discipline that deals with the building of software systems which are so large that they are built by a team or teams of engineers.” [Ghezzi, Jazayeri, Mandrioli]
40
Department of Informatics, UC Irvine SDCL Collaboration Laboratory Software Design and sdcl.ics.uci.edu 40 Software engineering “Multi-person construction of multi-version software.” [Parnas]
41
Department of Informatics, UC Irvine SDCL Collaboration Laboratory Software Design and sdcl.ics.uci.edu 41 Software engineering “Multi-person construction of multi-version software.” [Parnas]
42
Department of Informatics, UC Irvine SDCL Collaboration Laboratory Software Design and sdcl.ics.uci.edu 42 Software engineering “A discipline whose aim is the production of fault-free software, delivered on-time and within budget, that satisfies the user’s needs. Furthermore, the software must be easy to modify when the user’s needs change.” [Schach]
43
Department of Informatics, UC Irvine SDCL Collaboration Laboratory Software Design and sdcl.ics.uci.edu 43 Software engineering “A discipline whose aim is the production of fault-free software, delivered on-time and within budget, that satisfies the user’s needs. Furthermore, the software must be easy to modify when the user’s needs change.” [Schach]
44
Department of Informatics, UC Irvine SDCL Collaboration Laboratory Software Design and sdcl.ics.uci.edu 44 What is Software Engineering? Informatics 43: The process of constructing software. Phases of development other than programming. Principles and qualities of enduring value.
45
Department of Informatics, UC Irvine SDCL Collaboration Laboratory Software Design and sdcl.ics.uci.edu 45 Good luck on Test 2 Enjoy your break!
Similar presentations
© 2025 SlidePlayer.com. Inc.
All rights reserved.