- Количество слайдов: 84
Methodology for Information Systems Project Management Chapter 4: James R. Burns
Some PM Humor n n A badly planned project will take three times longer than expected – a well planned project only twice as long as expected. The more you plan the luckier you get. n At the heart of every large project are many small projects trying to get out. n The nice thing about not planning is that failure comes as a complete surprise rather than being preceded by a period of worry and depression.
The Real Software Development Process Out of jest and with tongue firmly in cheek, someone suggested the following software development process: n n n n n 1. Order the T-shirts for the development team 2. Announce availability of the product (This helps to motivate the team. ) 3. Write the code (Let’s get with it!) 4. Write the manual 5. Hire the project manager 6. Spec the software (Writing the specs after the code helps to ensure that the software meets the specifications. ) 7. Ship 8. Test (The customers are a big help with this step. ) 9. Identify bugs as potential enhancements 10. Announce the upgrade program (charge customers $ for upgrades)
Summary of Today’s Lecture n n n What do we mean by methodology? What are some ‘typical’ IT Project Types? The Generic Lifecycle model
Introduction: The Methodology Choice Becomes the Process n Indigenous to every project are its processes: the methodologies by which the project is brought to fruition n METHODOLOGY becomes the PROCESS n n n When implementation and execution of the methodology begins In this chapter we discuss the major phases of each project type We do not give you the entire WBS--just the top levels
What are some IT Project Types? ? n n n Enterprise Resource Planning Enterprise Architecture Determination Re-engineering projects Agile Development Projects Product selection n n n Component configuration projects Conversion projects Maintenance projects Component integration projects Internet Development projects Mobile Application Development Projects Cloud applications
Planning (Development) n n n Requirements are determined Project team is selected Resources are negotiated Team is formed, stormed, normed and ready to perform Formal Project plans are determined Formal Budgets are prepared
Executing (Implementation) n n n Where the project ramps up And begins to fulfill its phases Likened to execution in a sports activity Produces the project product Change management becomes especially important here
Closure and Termination (Close-out) n n n Document lessons learned History database Postmortem meeting Signature signoffs Get paid
Software Development Process Models--Boehm n n n WE’RE TALKING ABOUT THE EXECUTING STAGE HERE Code-and-fix model Waterfall model Evolutionary model Transform model Spiral model
Code-and-fix Model n n Write some code Then think about requirements, design, test and maintenance later After a number of fixes, code was poorly structured Used well before structured programming was invented
Waterfall Model n Definition u n n n If DEFINITION takes 2 months, then the project is roughly ___ long Analysis Design Construction Test Operation Maintenance
Following PMBOK n Predictive Methodologies u u u n Waterfall Evolutionary Spiral Adaptive Methodologies u Agile Methodologies F F F Scrum RUP Extreme Programming
The Waterfall Staircase Definition of Requirements Analysis Design Construction System Integration Testing Acceptance Testing Implementation Operation
Waterfall Model n n Required in all government software contracting Document-driven Good for developing something with fixed requirements--a new AI inference engine, a new compiler, a new database engine PROBLEMS: Expensive and time consuming because of its dependence on fully elaborated documents, curtails testing until near the end
The Standard Waterfall Model n n Better than old “CODE AND FIX” approach A manufacturing model for software CASE tools were developed to support it: TI’s IEF—sold in 1994 to Sterling Software Basis for most software acquisition standards in government
The Standard Waterfall Model, Cont’d n n n Too expensive for small projects Still used for project estimation (cost and duration) of large projects Doesn’t get used in practice very often any more
Evolutionary Process Model n n Better than WATERFALL for interactive end-user software development Ideally matched to fourth-generation language applications Also works well when users say “I can’t tell you what I want, but I’ll know it when I see it. ” Gives users a rapid initial operational prototype that they can play with and react to, even improve upon
The Evolutionary Process Model n n NOT MUCH MORE THAN OLD “CODE AND FIX” APPROACH Assumes user’s operational system will be flexible enough to accommodate unplanned evolution paths. n The above assumption is bad, because frequently, several independently evolved applications must now be integrated n Temporary work-arounds for software deficiencies increasingly solidify into unchangeable constraints on evolution
Transform Model n n Endeavors to address the difficulties associated with the code-and-fix, waterfall, and evolutionary models. Assumes the existence of a software module that can “parse, interpret and compile” written specifications automatically into machine code There is no 3 GL code (COBOL, Fortran) or 4 GL code (visual languages) The specifications are transformed directly to machine code
The Transform Model n Steps are: u u u Formal specification of the desired product Automatic transformation of the specification into code An iterative loop is necessary to improve the performance Exercise of the resulting product, and An outer iterative loop to adjust the specification based on the resulting operational experience
The Transform Model, Cont’d n n Avoids the difficulty of having to modify code that has become poorly structured through repeated re-optimization, since the modifications are made to the specification Avoids the extra time and expense involved in intermediate design, code and test activities
A Pervasive Problem n n How to enable users to create their own apps After all, there just aren’t enough developers around Ten years ago, the Air Force said it needed 1 out of every 5 HS graduates just to maintain its codes SOLUTION: Let users write their own specifications and then transform those same specifications directly to code
Did it work? n n n No! Specifications must be carefully written in a compiler-compatible format-the specifications become the program. Users have to learn a specification language --same as learning a 3 GL. Like the evolutionary model, it did not accommodate unplanned evolutionary paths well. Won’t work for Large-Scale Development
The Spiral Model (Boehm, 1988) n Overcomes most of these shortcomings and addresses these questions n What shall we do next? How long shall we continue doing it? Radial dimension represents the cumulative cost incurred in accomplishing the steps to date Angular dimension represents the progress made in completing each cycle of the spiral. n n n
Spiral Model n n n Can accommodate most previous development methodologies as special cases Is a risk-driven methodology, not a document-driven one Endeavors to depict both the passage of time and the accumulation of expenditure
Spiral Model, Continued n n n Radial dimension represents the cumulative cost incurred in accomplishing the steps to date Angular dimension represents the progress made in completing each cycle of the spiral. The methodology is dynamic and dependent upon the relative risks remaining
Each Loop of the Spiral Model n n n Identifies the objectives of the product being elaborated Identifies the alternatives to implementation Determines the constraints imposed on the alternatives Evaluates the alternatives relative to the objectives and the constraints Dynamically chooses methodological detail needed to alleviate perceived sources of risk
How is risk mitigated? n If there is risk associated n with the specification of the product, then reference checking, administering user questionnaires, analytic modeling, or combinations of these should be used to mitigate the risk If there is risk associated with the ultimate design of the product, then prototyping, simulation, or benchmarking should be utilized to mitigate this risk.
How is risk mitigated? n If user-interface risks strongly dominate product considerations, or there are internal interface control risks, then the next step may be to use evolutionary development
Figure 2 -3. Spiral Model of Software Dev.
Advantages of Spiral Model n n Applies to maintenance as well as to development Incorporates prototyping as a risk-reduction option at any stage Accommodates reworks or go-backs to earlier stages Focuses early attention on reuse of existing software
More Advantages of the Spiral Model n n Accommodates preparation for life-cycle evolution, growth Provides a mechanism for incorporating software quality objectives Focuses on eliminating errors and unattractive alternatives early More adaptable to projects other than development than the waterfall model, which applies only to development
More Advantages of the Spiral Model n n Provides a viable framework for integrating hardware-software system development Accommodates CASE and other transform tools
Disadvantages of the Spiral Model n n Doesn’t work with fixed-price contracts well Use by outside contractors and system integrators is difficult, therefore Relies on project professionals with riskassessment expertise If there aren’t any risks, it doesn’t work well
The Dimensions Waterfall High Ceremony Low Ceremony Iterative
Process Map Waterfall Few risks, late integration and testing High Ceremony Low Ceremony Heavy Doc, heavy process discipline, CCB Little Doc, light process discipline Iterative Risk Driven, Continuous integration and testing
Agile/Adaptive Software Development n Software is developed in increments using an iterative approach u u n Learning takes place all along the way u n n Architecture and Backbone first User interfaces next Important functionality next Less important functionality last Important components may be improved before less important components are even started Provides a naive user with an early experience with the software. Endeavors to deliver business value early.
More Agile/Adaptive Software Development using Scrum An iteration (sprint) lasts one to four weeks n Each iteration passes through a full software development cycle including planning, requirements analysis, design, coding, testing, and documentation. The goal is to have an available release (without bugs) at the end of each iteration. n At the end of each iteration, the team reevaluates project priorities. n Agile/Adaptive methods emphasize face-to-face communication over written documentation. n
Principles Behind the Agile/Adaptive Manifesto n n n Customer satisfaction by rapid, continuous delivery of useful software. Working software is delivered frequently (weeks rather than months). Working software is the principal measure of progress. Even late changes in requirements are welcomed. Close, daily cooperation between business people and developers is strongly encouraged. Face-to-face conversation is the best form of communication.
More Principles behind Agile/Adaptive Development n n n Projects are built around motivated individuals, who can be trusted. Continuous attention to technical excellence and good design is required. Simplicity is a hallmark. Self organizing teams are always used. Regular adaptation to changing circumstances is accommodated.
Iterative, Agile/Adaptive Processes n n Rational Unified Process (RUP) Dynamic Systems Development Method (DSDM) Extreme Programming (XP) Crystal n Scrum
The Home Ground n n For Agile/Adaptive software development, the home ground is a culture that thrives on chaos, low criticality, a small number of senior developers are used, and requirements change very often, applications are small. For plan-driven (Predictive) methods (such as the Waterfall Model), the home ground is high criticality, junior developers, requirements don't change, a large number of developers, and a culture that demands order.
Agile Project Management n n Agile means being able to move quickly and easily, but some people feel that project management, as they have seen it used, does not allow people to work quickly or easily. Early software development projects often used a waterfall approach, as defined earlier in this chapter. As technology and businesses became more complex, the approach was often difficult to use because requirements were unknown or continuously changing. n Agile today means using a method based on iterative and incremental development, in which requirements and solutions evolve through collaboration. n See the Resources tab from www. pmtexts. com for more info
Agile Makes Sense for Some Projects, But Not All n n Many seasoned experts in project management warn people not to fall for the hype associated with Agile. For example, J. Leroy Ward, Executive Vice President at ESI International, said that “Agile will be seen for what it is … and isn’t…. Project management organizations embracing Agile software and product development approaches will continue to grow while being faced with the challenge of demonstrating ROI through Agile adoption. ”* *Agile Manifesto, www. agilemanifesto. org.
Manifesto for Agile Software Development n n n In February 2001, a group of 17 people that called itself the Agile Alliance developed and agreed on the Manifesto for Agile Software Development, as follows: “We are uncovering better ways of developing software by doing it and helping others do it. Through this work we have come to value: Individuals and interactions over processes and tools *Agile Manifesto, www. agilemanifesto. org.
Agile Manifesto: We value-n n n Working software over comprehensive documentation Customer collaboration over contract negotiation Responding to change over following a plan”* *Agile Manifesto, www. agilemanifesto. org.
Scrum n n According to the Scrum Alliance, Scrum is the leading agile development method for completing projects with a complex, innovative scope of work. The term was coined in 1986 in a Harvard Business Review study that compared highperforming, cross-functional teams to the scrum formation used by rugby teams.
Fig. 2 -6, Schwalbe. Scrum Framework Information Technology Project Management, Eighth Edition
Kanban n n Technique that can be used in conjunction with scrum Developed in Japan by Toyota Motor Corporation Uses visual cues to guide workflow Kanban cards show new work, work in progress, and work completed 51
Agile, the PMBOK® Guide, and a New Certification n n The PMBOK® Guide describes best practices for what should be done to manage projects. Agile is a methodology that describes how to manage projects. n The Project Management Institute (PMI) recognized the increased interest in Agile, and introduced a new certification in 2011 called Agile Certified Practitioner (ACP). n Seasoned project managers understand that they have always had the option of customizing how they run projects, but that project management is not easy, even when using Agile. 52
Agile Project Management u Is related to the rolling wave planning and scheduling project methodology. F Uses iterations (“time boxes”) to develop a workable product that satisfies the customer and other key stakeholders. F Stakeholders and customers review progress and reevaluate priorities to ensure alignment with customer needs and company goals. F Adjustments are made and a different iterative cycle begins that subsumes the work of the previous iterations and adds new capabilities to the evolving product.
Iterative, Incremental Product Development
Hub Project Management Structure
More SCRUM n n n Scrum is an Agile/Adaptive development methodology, implying low ceremony (little documentation, face-to-face meetings). Scrum is a process skeleton that includes a set of practices and predefined roles. There are two types of roles used in connection with Scrum, those who are committed are called ‘pigs’ and those who are involved who are called ‘chickens. ’ Stakeholders are considered chickens whereas the project team and Scrum master (project manager) are called ‘pigs. ’
Still More SCRUM n n n Scrum consists of a series of sprints. Each sprint is a period of 15 to 30 days, during which the team creates a usable module of software. Scrum is considered ‘easy to learn’ and doesn’t require a lot of training to start using it. Sprint periods of 30 days are similar to the monthly time-boxes used in RAD.
SCRUM Meetings n n n n Each day during the sprint, a project status meeting occurs. This is called a SCRUM Meeting. The procedure for a SCRUM Meeting is the following : 1) the meeting starts precisely on time with teamdecided punishments for tardiness 2) all are welcome, but only “pigs” may speak 3) the meeting is time-boxed at fifteen minutes regardless of the team’s size 4) all attendees should stand 5) the meeting should happen at the same location and same time every day
SCRUM…. In Summary n n n n Scrum is an Agile/Adaptive process to manage and control development work. Scrum is a team-based approach to iteratively, incrementally develop systems and products when requirements are rapidly changing. Scrum is a process that controls the chaos of conflicting interests and needs. Scrum is a way to improve communications and maximize co-operation. Scrum is a way to detect and cause the removal of anything that gets in the way of developing and delivering products. Scrum is a way to maximize productivity. Scrum is scalable from single projects to entire organizations. Scrum has controlled and organized development and implementation for multiple interrelated products and projects with over a thousand developers and implementers.
Ignore the HIDDEN slides on the RUP
Another IT Project Type: Conversion n Slam-dunk Parallel Pilot
Another IT Project Type: System Integration and Test n n Component selection Component integration and testing
Another IT Project Type: Process Reengineering—Michael Hammer n n n 1) determine measures of performance 2) install measures of performance 3) delineate entire existing process in all its gory detail 4) perform process value analysis and activity-based costing 5) benchmark processes by comparison with other processes
More Process Reengineering n n n 6) design re-invented process 7) simulate re-invented process 8) prepare report with recommendations 9) upgrade the software applications that support the re-engineered process 10) install re-invented process 11) measure improvements
Another IT Project Type: Enterprise Integration n n The ability to read-from and write to all of the apps and data sources across the enterprise Application integration u n Use a common SOFTWARE BUS to “glue” them together Data warehousing
More Enterprise Integration n Workgroup/Workflow Apps Messaging systems Data federation u performs integration while leaving the source data in place
Another IT Project Type: System Maintenance n n Can use Spiral model here Software doesn’t need to be greased, like something mechanical does, so what do we mean by maintenance of software?
Selection Methodology: For Software, Processes and Projects n n n Could use MAUT, as we previously suggested Could use ROI Could use IRR
This is it: no more time…. no more slides in this section…. This year….
How do we get applications out the door in a timely manner? n n n Reuse as much as possible--data and presentation components Intuitive Object-Oriented approach is the answer Use Dupont’s approach u u Calendar-driven development Trade time for functionality Use time boxes (three months, usually) can drop low-priority functionality
One of our Goals: Flexibility n We want a methodology that is so flexible that the requirements can change all during the development process, yet we can still meet the needs of the end users at the time of cut-over (i. e. , deliver the product on time and within budget)
User Prototypes n n n First couple of iterations are really prototypes--fifth iteration is the final product Limit cosmetic iterations to just two MDI frames should not be coupled, should possess very low cohesion
The Goal n n n Get the application living quickly Learn from it Then enhance it Time is more important than functionality Use two three-month time-boxes When the final version of the product is delivered the end of the second three-months, users will have a much greater understanding of their requirements
Creating Object Repositories n n Must use the old software factory model Deposit well-documented objects, COMPONENTS in the repository Encourage developers to reuse the objects by incentive/reward mechanisms Must avoid re-inventing objects within all the functions of an organization
Standards should be devised n Version control--allowing for all versions of the module to be tracked
Screens/Pages n n n Each member of the team delivers from 1 to three screens (pages) daily A significant release should be forthcoming each week Each developer’s assigned tasks should be broken down into chunks of functionality that must be delivered by certain due dates
Selection Methodology: For Software, Processes and Projects n n n Define the application to be computerized Develop a list of COTS packages that is available to support the app Gather information about the COTS packages Narrow the list of possible choices down to less than a half dozen Obtain hands-on demonstrations of the few remaining packages
Selection Methodology, Cont’d n n n Of those that remain, perform a final detailed evaluation Make a decision Purchase the selected COTS package Learn to use the package Implement the package
Operational Issues -- Brooks n Another Software guru like Boehm
Software Development -- Brooks n n What is the problem with hiring additional people on a project that is behind schedule? Under what circumstances are men and man -hours interchangeable? How much time should be set aside for testing and integration, according to Brooks? What are some good ways to organize work packages to avoid some of the problems Brooks is talking about?
Questions n n n All programmers are ____. When schedule slippage occurs, the natural thing is to ____. What are three stages of creative activity? These are analogous to ____? Brooks says that the programmer builds from ____. F pure thought stuff; concepts and flexible representations. However, today this is not true.
Questions, Cont’d n Cost varies as the number of persons and the number of months • However, progress does not. n Can we use the man-month as a unit for sizing a job? • No. It is too dangerous n People and months are inter-changeable only when a task can be partitioned among many workers with _____. • No communication between them n The added burden of communication is made up of _____. • two parts: training and intercommunication. n Long projects can expect a turnover of ___% a year. • 20
Questions, Cont’d n How much of the total time does Brooks devote to Definition, Analysis and Design? • 1/3 n How much time to coding? • 1/6 to Coding n How much time to testing? • 1/4 to component test and early system test • 1/4 to total system test