Systems Analysis and Design Alan Dennis Barbara Haley
Systems Analysis and Design Alan Dennis, Barbara Haley Wixom, and Roberta Roth John Wiley & Sons, Inc. Slides by Candace S. Garrod Red Rocks Community College Modified by Yusuf Altunel To be presented in CSE 440 Systems Analysis and Design İKU Department of Computer Engineering 3 -1 Power. Point Presentation for Dennis, Wixom, & Roth Systems Analysis and Design, 3 rd Edition Copyright 2006 © John Wiley & Sons, Inc. All rights reserved. .
Project Management Chapter 3 3 -2 The project should be manageable • Estimation • Planning • Resource Management • Project Tracking • Control • Coordination Power. Point Presentation for Dennis, Wixom, & Roth Systems Analysis and Design, 3 rd Edition Copyright 2006 © John Wiley & Sons, Inc. All rights reserved. .
Chapter Outline Identifying project size Creating and managing the workplan Staffing the project Coordinating project activities 3 -3 Power. Point Presentation for Dennis, Wixom, & Roth Systems Analysis and Design, 3 rd Edition Copyright 2006 © John Wiley & Sons, Inc. All rights reserved.
Key Definitions Project management is the process of planning and controlling the development of a system with the right functionality within a specified timeframe at a minimum cost A project manager manages and coordinates the hundreds of tasks and roles (people) 3 -4 Power. Point Presentation for Dennis, Wixom, & Roth Systems Analysis and Design, 3 rd Edition Copyright 2006 © John Wiley & Sons, Inc. All rights reserved.
Key Steps in Managing Projects Identifying project size Creating and managing the workplan Staffing the project Coordinating project activities 3 -5 Power. Point Presentation for Dennis, Wixom, & Roth Systems Analysis and Design, 3 rd Edition Copyright 2006 © John Wiley & Sons, Inc. All rights reserved.
IDENTIFYING PROJECT SIZE 3 -6 Power. Point Presentation for Dennis, Wixom, & Roth Systems Analysis and Design, 3 rd Edition Copyright 2006 © John Wiley & Sons, Inc. All rights reserved. .
Project Manager’s Balancing Act Project Management involves making trade-offs… Project Size 3 -7 e m Ti ec t Pr oj ost ect C Proj Modifying one element requires adjusting the others Power. Point Presentation for Dennis, Wixom, & Roth Systems Analysis and Design, 3 rd Edition Copyright 2006 © John Wiley & Sons, Inc. All rights reserved.
Project Estimation The process of assigning projected values for time and effort Sources of estimates Methodology in use Previous projects Experienced developers Estimates begin as a range become more specific as the project progresses 3 -8 Power. Point Presentation for Dennis, Wixom, & Roth Systems Analysis and Design, 3 rd Edition Copyright 2006 © John Wiley & Sons, Inc. All rights reserved.
Project Time Using the Planning Phase Approach 3 -9 Power. Point Presentation for Dennis, Wixom, & Roth Systems Analysis and Design, 3 rd Edition Copyright 2006 © John Wiley & Sons, Inc. All rights reserved.
Project Estimation Using the Function Point Approach * Function Point Estimation is found by Capers Jones (October of 1979) and SPR 3 - 10 Power. Point Presentation for Dennis, Wixom, & Roth Systems Analysis and Design, 3 rd Edition Copyright 2006 © John Wiley & Sons, Inc. All rights reserved.
Unadjusted Function Point Calculation 3 - 11 Power. Point Presentation for Dennis, Wixom, & Roth Systems Analysis and Design, 3 rd Edition Copyright 2006 © John Wiley & Sons, Inc. All rights reserved.
Measurement Parameters-1 Number of user inputs. Each user input to provide distinct application oriented data to the software Sources: arrive from another system! be entered by the user from input screens! Inputs should be distinguished from inquiries are counted separately! Number of user outputs. to provide application oriented information to the user derived variables calculated within the system transferred to another system data used to prepare a report, … individual data items within a report are not counted separately! reports, screens, error messages, etc. 12
Measurement Parameters-2 Number of user inquiries. an on-line input results in the generation of software response retrieve data from internal files or databases but do not change them! Each distinct inquiry is counted. Number of files. Data stored entirely within the system Types: logical master files flat files database tables… Number of external interfaces. All machine readable interfaces e. g. , data files on storage media used to transmit information to another system. 13
Example: Spell Checker user inputs. The sentences entered to check their spellings user outputs. Error message with suggested alternative spellings. user inquiries. A lookup table for each word against the internal dictionary files. Standard dictionary User entered dictionary external interfaces. External dictionary i. e. www. wiktionary. org to reference for more information 14
Complexity of Parameters: Averages User inputs, outputs, & queries. 6 -20 data different data elements first name, last name, city, etc. reference to or update 2 -3 files Files and interfaces. 2 -5 logical groups of data elements 20 -50 number of different data element types Below these numbers: Rate is Low Over these numbers: Rate is High 15
System Characteristics 1. Data Communications: Are data communications required? 2. Distributed functions: Are there distributed processing functions? 3. Performance: Is performance critical? 4. Heavy used configuration : Is the system designed to easily be configured to satisfy different type of requirements? 5. Transaction rate: Does the on-line data entry require the input transaction to be built over multiple screens or operations? 6. Online data entry: Does the system require on-line data entry? 7. End user efficiency: Will the system run in an existing, heavily utilized operational environment? 8. Online update: Are the (master) files updated on-line? 9. Complex processing: Is the internal processing complex? 10. Reusability: Is the code designed to be reusable? 11. Installation ease: Are conversion and installation included in the design? 12. Operational ease: Is the application designed for easy of use of the user? 13. Multiple sites: Is the system designed for multiple installations in different organizations? 14. Facilitate change: Is the application designed to facilitate change? 15. Extensibility: Is the system is designed to easily be extended in future versions? 16. Backup & Recovery: Does the system require reliable backup and recovery? 16
Rating System Characteristics Answer questions for each of the characteristics … (2) How are distributed data functions handled? (9) Does the application have extensive logic processing? (16) To what extent are start-up, backup, and recovery procedures automatic? … Assign a rate to each of characteristics 0: no effect on the complexity (not applicable) 1: small effect (not so essential) 2: small-to-medium effect (not critically essential ) 3: medium effect (essential) 4: high effect (very important) 5: great effect on the characteristic/absolutely essential 17
Function Point Estimation Worksheet Step One – Estimate System Size (Overall System - Example) 1. Data Communications 2. Distributed functions 3. Performance 4. Heavy use configuration 5. Transaction rate 6. Online data entry 7. End-user efficiency 8. Online update 9. Complex processing 10. Reusability 11. Installation ease 12. Operational ease 13. Multiple sites 14. Facilitate change 15. Extensibility 16. Backup & Recovery Total Processing Complexity (PC): 18 3 2 0 0 0 1 0 0 0 8
Factors affecting software engineering productivity Factor Description Application domain experience Knowledge of the application domain is essential for effective software development Engineers who already understand a domain is likely to be the most productive. Process quality The development process used can have a significant effect on productivity. Project size The larger a project, the more time required for team communications. Less time is available for development so individual productivity is reduced. Technology support Good support technology such as CASE tools and configuration management systems can improve productivity. Working environment A quiet working environment with private work areas contributes to improved productivity. 3 - 19 Power. Point Presentation for Dennis, Wixom, & Roth Systems Analysis and Design, 3 rd Edition Copyright 2006 © John Wiley & Sons, Inc. All rights reserved.
Function Point Estimation Adjusting the Function Points Total Processing Complexity (PC): (From Step 2) ____ 8 ____ Adjusted Processing Complexity (PCA) = 0. 65 + (0. 01 * __8__ ) Total Adjusted Function Points: 0. 73 * 338 = TUFP (From Step 1) 20 247
Converting Function Points to Lines of Code 3 - 21 Power. Point Presentation for Dennis, Wixom, & Roth Systems Analysis and Design, 3 rd Edition Copyright 2006 © John Wiley & Sons, Inc. All rights reserved.
Converting Function Points to Lines of Code Pressman pp 94 22
Converting Function Points to Lines of Code Language Average Source Level Statements Per Function Point 1 st Generation Languages (default) 1 320 2 nd Generation Languages (default) 3 107 3 rd Generation Languages (default) 4 80 4 th Generation Languages (default) 16 20 According to SPR (Software Productivity Research) http: //www. spr. com/products/programming. shtm 23
Function Point Estimation Step Two – Estimate Effort Required COCOMO model For small to moderate size project 100, 000 lines of code, 10 or fewer programmers is very simple (Effort in = 1. 4 * thousands-of-lines-of-code Person Months) Example: If LOC = 10000 Then. . . Effort = (1. 4 * 10) 3 - 24 = 14 Person Months Power. Point Presentation for Dennis, Wixom, & Roth Systems Analysis and Design, 3 rd Edition Copyright 2006 © John Wiley & Sons, Inc. All rights reserved.
Function Point Estimation Step Three - Schedule Time Rule of thumb for estimation Schedule Time (months) = 3. 0 * person-months 1/3 14 person-months => Schedule to take a little more than 7 months 3 - 25 Power. Point Presentation for Dennis, Wixom, & Roth Systems Analysis and Design, 3 rd Edition Copyright 2006 © John Wiley & Sons, Inc. All rights reserved.
CREATING AND MANAGING THE WORK PLAN 3 - 26 Power. Point Presentation for Dennis, Wixom, & Roth Systems Analysis and Design, 3 rd Edition Copyright 2006 © John Wiley & Sons, Inc. All rights reserved. .
Project Scheduling Task Identification Project Staffing Project Tracking 27
Identifying Tasks Methodology Using standard list of tasks Top-down approach Identify highest level tasks Break them into increasingly smaller units Organize into work breakdown structure 3 - 28 Power. Point Presentation for Dennis, Wixom, & Roth Systems Analysis and Design, 3 rd Edition Copyright 2006 © John Wiley & Sons, Inc. All rights reserved.
Identifying Tasks Task Number 3 - 29 Task Name Duration in weeks Dependency Status Power. Point Presentation for Dennis, Wixom, & Roth Systems Analysis and Design, 3 rd Edition Copyright 2006 © John Wiley & Sons, Inc. All rights reserved.
Project Workplan Work breakdown structure List all tasks Add: Duration of task Current task status Task dependencies Milestone (dates) 3 - 30 Power. Point Presentation for Dennis, Wixom, & Roth Systems Analysis and Design, 3 rd Edition Copyright 2006 © John Wiley & Sons, Inc. All rights reserved.
A Task Example 3 - 31 Work Plan Information Example Name of task Start date Completion date Person assigned Deliverable(s) Completion status Priority Resources needed Estimated time Actual time Perform economic feasibility Jan 05, 2005 Jan 19, 2005 Project sponsor: Mary Smith Cost-benefit analysis Open High Spreadsheet 16 hours 14. 5 hours Power. Point Presentation for Dennis, Wixom, & Roth Systems Analysis and Design, 3 rd Edition Copyright 2006 © John Wiley & Sons, Inc. All rights reserved.
Tracking Project Tasks Gantt Chart Bar chart format Useful to monitor project status PERT Chart Flowchart format Illustrates task dependencies critical path 3 - 32 Power. Point Presentation for Dennis, Wixom, & Roth Systems Analysis and Design, 3 rd Edition Copyright 2006 © John Wiley & Sons, Inc. All rights reserved.
Tracking Tasks Using Gantt Chart 3 - 33 Power. Point Presentation for Dennis, Wixom, & Roth Systems Analysis and Design, 3 rd Edition Copyright 2006 © John Wiley & Sons, Inc. All rights reserved.
Tracking Tasks Using PERT Chart 3 - 34 Power. Point Presentation for Dennis, Wixom, & Roth Systems Analysis and Design, 3 rd Edition Copyright 2006 © John Wiley & Sons, Inc. All rights reserved.
Margins of Error in Cost and Time Estimates 3 - 35 Power. Point Presentation for Dennis, Wixom, & Roth Systems Analysis and Design, 3 rd Edition Copyright 2006 © John Wiley & Sons, Inc. All rights reserved.
Managing Scope creep new requirements! Defer additional requirements as future system enhancements 3 - 36 Power. Point Presentation for Dennis, Wixom, & Roth Systems Analysis and Design, 3 rd Edition Copyright 2006 © John Wiley & Sons, Inc. All rights reserved.
Timeboxing Time-oriented planning instead of task-oriented approach Reason: time is limited! Fixed deadline Reduced functionality Prefer the most critical ones! Satisfies the business Providing a product Within expected time frame 3 - 37 Power. Point Presentation for Dennis, Wixom, & Roth Systems Analysis and Design, 3 rd Edition Copyright 2006 © John Wiley & Sons, Inc. All rights reserved.
Timeboxing Steps 1. Set delivery date 2. 3. 4. 5. 6. 3 - 38 Deadline should not be impossible Should be set by development group Prioritize features by importance Build the system core Postpone unfinished functionality Deliver the system with core functionality Repeat steps 3 -5 to add refinements and enhancements Power. Point Presentation for Dennis, Wixom, & Roth Systems Analysis and Design, 3 rd Edition Copyright 2006 © John Wiley & Sons, Inc. All rights reserved.
STAFFING THE PROJECT 3 - 39 Power. Point Presentation for Dennis, Wixom, & Roth Systems Analysis and Design, 3 rd Edition Copyright 2006 © John Wiley & Sons, Inc. All rights reserved. .
Staffing Attributes Staffing levels will change over a project’s lifetime Adding staff may add more overhead Using teams under 8 -10 people can reduce complexity communication is effective in small teams If more people required Create sub-teams 3 - 40 Power. Point Presentation for Dennis, Wixom, & Roth Systems Analysis and Design, 3 rd Edition Copyright 2006 © John Wiley & Sons, Inc. All rights reserved.
Increasing Complexity with Larger Teams 3 - 41 Power. Point Presentation for Dennis, Wixom, & Roth Systems Analysis and Design, 3 rd Edition Copyright 2006 © John Wiley & Sons, Inc. All rights reserved.
Key Definitions The staffing plan lists the roles describes the reporting structure The project charter describes the project’s objectives and rules A functional lead manages a group of analysts A technical lead oversees progress of programmers and technical staff members 3 - 42 Power. Point Presentation for Dennis, Wixom, & Roth Systems Analysis and Design, 3 rd Edition Copyright 2006 © John Wiley & Sons, Inc. All rights reserved.
A Possible Team Configuration 3 - 43 Power. Point Presentation for Dennis, Wixom, & Roth Systems Analysis and Design, 3 rd Edition Copyright 2006 © John Wiley & Sons, Inc. All rights reserved.
Motivation Use monetary rewards cautiously Use intrinsic rewards Recognition Achievement The work itself Responsibility Advancement Chance to learn new skills 3 - 44 Power. Point Presentation for Dennis, Wixom, & Roth Systems Analysis and Design, 3 rd Edition Copyright 2006 © John Wiley & Sons, Inc. All rights reserved.
Handling Conflict Clearly define project plans Recognize project importance to organization Project charter listing norms and groundrules Develop schedule commitments ahead of time Forecast other priorities and their possible impact on the project 3 - 45 Power. Point Presentation for Dennis, Wixom, & Roth Systems Analysis and Design, 3 rd Edition Copyright 2006 © John Wiley & Sons, Inc. All rights reserved.
COORDINATING PROJECT ACTIVITIES Standards Documentation Managing Risks 3 - 46 Power. Point Presentation for Dennis, Wixom, & Roth Systems Analysis and Design, 3 rd Edition Copyright 2006 © John Wiley & Sons, Inc. All rights reserved. .
Standards Industry standards ISBN Person Names. . . Formal rules for naming files Forms indicating goals reached Programming guidelines Comments Templates of Documents 3 - 47 Power. Point Presentation for Dennis, Wixom, & Roth Systems Analysis and Design, 3 rd Edition Copyright 2006 © John Wiley & Sons, Inc. All rights reserved.
Documentation Stored in project binder Documentation is critical Year 2000 crisis Good project teams learn how to document Continual updating 3 - 48 Power. Point Presentation for Dennis, Wixom, & Roth Systems Analysis and Design, 3 rd Edition Copyright 2006 © John Wiley & Sons, Inc. All rights reserved.
Managing Risk assessment: A Document tracks potential risks potential impact on the project Ways to deal with risks Publicized Avoided Eliminated Actions to reduce risks Prioritize risks according to the magnitude Importance Define scenarios to deal with risks Continuously check the occurrences of risks 3 - 49 Power. Point Presentation for Dennis, Wixom, & Roth Systems Analysis and Design, 3 rd Edition Copyright 2006 © John Wiley & Sons, Inc. All rights reserved.
Risk Management Activities Risk Identification Risk Refinement Risk Estimation Risk Avoidance Planning Mitigation Scenarios Risk Monitoring Risk Mitigation Software safety and hazards analysis 3 - 50 Power. Point Presentation for Dennis, Wixom, & Roth Systems Analysis and Design, 3 rd Edition Copyright 2006 © John Wiley & Sons, Inc. All rights reserved.
Risk analysis and management Produce risk assessment document tracks potential risks potential impact on the project Define project risks Set the importance according to magnitude importance Define the damage risk causes Set risk mitigation scenarios Set actions to prevent risks Set actions to reduce risks Define the scenarios applied when risk happens Follow up risk’s realization Decide if the risk happens Activate the risk mitigation scenario 51
The Risk Management Process 3 - 52 Power. Point Presentation for Dennis, Wixom, & Roth Systems Analysis and Design, 3 rd Edition Copyright 2006 © John Wiley & Sons, Inc. All rights reserved.
Some of Possible Risks 3 - 53 Risk type Description Staff turnover Project Experienced staff will leave the project before it is finished. Management change Hardware unavailability Requirements change Specification delays Size underestimate CASE tool underperformance Technology change Product competition Project There will be a change of organizational management with different priorities. Hardware which is essential for the project will not be delivered on schedule. Project and Product There will be a larger number of changes product to the requirements than anticipated. Specifications of essential interfaces are not available, on schedule. Business The underlying technology on which the system is built is superseded by new technology. A competitive product is marketed before the system is completed. Business The size of the system has been underestimated. Product CASE tools which support the project do not perform as anticipated. Power. Point Presentation for Dennis, Wixom, & Roth Systems Analysis and Design, 3 rd Edition Copyright 2006 © John Wiley & Sons, Inc. All rights reserved.
Classic Mistakes Overly optimistic schedule Failing to monitor schedule Failing to update schedule Adding people to a late project 3 - 54 Power. Point Presentation for Dennis, Wixom, & Roth Systems Analysis and Design, 3 rd Edition Copyright 2006 © John Wiley & Sons, Inc. All rights reserved.
Summary Project management is critical to successful development of new systems Project management involves planning, controlling and reporting on time, labor, and costs. 3 - 55 Power. Point Presentation for Dennis, Wixom, & Roth Systems Analysis and Design, 3 rd Edition Copyright 2006 © John Wiley & Sons, Inc. All rights reserved.
Copyright © 2006 John Wiley & Sons, Inc. All rights reserved. Reproduction or translation of this work beyond that permitted in Section 117 of the 1976 United States Copyright Act without the express written permission of the copyright owner is unlawful. Request for further information should be addressed to the Permissions Department, John Wiley & Sons, Inc. The purchaser may make back-up copies for his/her own use only and not for redistribution or resale. The Publisher assumes no responsibility for errors, omissions, or damages, caused by the use of these programs or from the use of the information contained herein. 3 - 56 Power. Point Presentation for Dennis, Wixom, & Roth Systems Analysis and Design, 3 rd Edition Copyright 2006 © John Wiley & Sons, Inc. All rights reserved.
- Slides: 56