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Software Development Methodologies Lecturer:

Raman Ramsin

Lecture 19: Process AntiPatterns

Department of Computer Engineering

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Sharif University of Technology

Software Development Methodologies – Lecture 19 AntiPatternsAntiPatterns „^ Compiled and presented by Brown et al

in 1998

„^ Compiled

and presented by Brown et al. in 1998.

„^ "An AntiPattern describes a commonly occurring solution to a„^ An AntiPattern describes a commonly occurring solution to aproblem that generates decidedly negative consequences." „^ The AntiPattern may be the result of a manager or developer:^

not knowing any better, not having sufficient knowledge or experience in solving a particulartype of problem, or

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^ having applied a perfectly good pattern in the wrong context. Department of Computer Engineering

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Sharif University of Technology

Software Development Methodologies – Lecture 19 Process AntiPatterns: DevelopmentProcess

AntiPatterns: Development

„^ Lava Flow:

Dead code and forgotten design information is frozen in an ever-changing design. „ Ambiguous Viewpoint:

Object-oriented analysis and design models

presented without clarifying the viewpoint represented by the model. „ Golden Hammer:

A familiar technology or concept applied obsessively to many software problems. W lki^

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„^ Walking through a Minefield:

Using today’s software technology is

analogous to walking through a high-tech mine field: bugs abound. M^ h^

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„^ Mushroom Management:

Keeping system developers isolated from the

system’s end users.Department of Computer Engineering

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Sharif University of Technology

Software Development Methodologies – Lecture 19 Process AntiPatterns: Development –

Lava Flow

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„^ Lava Flow:

Dead code and forgotten design information is frozen in an ever- changing design. „ Causes:^ ^ R&D code placed into production without configuration management.

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^ Uncontrolled distribution of unfinished code. ^ Implementation of several trial approaches for implementing a function. ^ Single developer (lone wolf) design or written code ^ Single-developer (lone wolf) design or written code. ^ Lack of configuration management or process management policies. ^ Lack of architecture, or non-architecture-driven development. ^ Repetitive development process. ^ Architectural scars: Architectural mistakes not removed. „ To solve:

include a configuration management process that eliminates dead code and evolves or refactors design toward increasing quality. „ To avoid:

ensure that sound architecture precedes code development. Department of Computer Engineering

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Sharif University of Technology p^

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Software Development Methodologies – Lecture 19 Process AntiPatterns: Development –

Golden Hammer

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„^ Golden Hammer:

A^ Golden Hammer is a familiar technology

or concept applied obsessively to many software problems. „ "When your only tool is a hammer, everything else is a nail." „ Solution: „ Solution:^

^ expanding the knowledge of developers through education,t^

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training, and book study groups to expose developers toalternative technologies and approaches.

Department of Computer Engineering

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Sharif University of Technology

Software Development Methodologies – Lecture 19 Process AntiPatterns: Development –

Walking through a Minefield

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„^ Walking through a Minefield:

Using today’s software technology is

analogous to walking through a high-tech mine field: Numerous bugsare found in released software productsare found in released software products. „ Solution:^

^ Proper investment in software testing is required to make systemsrelatively bug-free. In some progressive companies, the size of testingstaff exceeds programming staffstaff exceeds programming staff.^ ^ The most important change to make to testing procedures isconfiguration control of test cases.configuration control of test cases.^ ^ automation of test execution and test design.Department of Computer Engineering

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Sharif University of Technology

Software Development Methodologies – Lecture 19 Process AntiPatterns: ArchitecturalProcess

AntiPatterns: Architectural

„^ Cover Your Assets:

Document

-driven software processes that

„^ Cover

Your Assets:

Document

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software processes that

produce less-than-useful requirements and specifications because theauthors evade making important decisions.^ hi^

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„^ Architecture by Implication:

the lack of architecture specifications

for a system under development. „ Design by Committee:

Design by Committee creates overly

„^ Design

by Committee:

Design

by Committee creates overly

complex architectures that lack coherence. „ Reinvent the Wheel:

The pervasive lack of experience transfer

„^ Reinvent

the Wheel:

The^ pervasive lack of experience transfer

between software projects leads to substantial reinvention. „ The Grand Old Duke of York:

Egalitarian software processes ofteng^

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ignore people’s talents to the detriment of the project: We needabstractionists as well as

implementationists.

Department of Computer Engineering

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Sharif University of Technology

Software Development Methodologies – Lecture 19 Process AntiPatterns: Architectural –

Cover Your Assets

„^ Cover Your Assets:

Document-driven software processes often produce

less than useful requirements and specifications because the authors evadeless-than-useful requirements and specifications because the authors evademaking important decisions.^ ^ In order to avoid making a mistake, the authors take a safer course andl b

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lt^ ti elaborate upon alternatives. „^ Solution:^ ^

Enforce the production of Architecture blueprints: abstractions of informationsystems that facilitate communication of requirements and technical plansbetween the users and developers.

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„^ An architecture blueprint is a small set of diagrams and tables thatcommunicate the operational, technical, and systems architecture of currentand future extensions to information systems.

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„^ A typical blueprint comprises no more than a dozen diagrams and tables,and can be presented in an hour or less as a viewgraph presentation. Department of Computer Engineering

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Sharif University of Technology

Software Development Methodologies – Lecture 19 Process AntiPatterns: Architectural –

Design By Committeeg

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„^ Design by Committee:

The classic AntiPattern from standards bodies,

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Design by Committee creates overly complex architectures that lackcoherence:^ ^ A complex software design that is the product of a committee process ^ A complex software design that is the product of a committee process.^ ^ It has so many features and variations that it is infeasible for any group ofdevelopers to realize the specifications in a reasonable time frame.^ ^ Even if the designs were possible, it would not be possible to test the full designdue to excessive complexity, ambiguities, overconstraint, and other specificationdefects.^ ^ The design would lack conceptual clarity because so many people contributed toit and extended it during its creation. „ Solution:Solution:^ ^ Clarification of architectural roles and improved process facilitation can refactorbad meeting processes into highly productive events.Department of Computer Engineering

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Sharif University of Technology

Software Development Methodologies – Lecture 19 Process AntiPatterns: Architectural –

Reinvent the Wheel

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„^ Reinvent the Wheel:

The pervasive lack of experience

transfer between software projects leads to substantialreinvention. „ “Our problem is unique.” „ Virtually all systems development is done in isolation of projectsand systems with overlapping functionality. „ Solution:^

^ Design knowledge buried in legacy assets can be leveraged to reducetime-to-market, cost, and risk.Department of Computer Engineering

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Sharif University of Technology

Software Development Methodologies – Lecture 19 Process AntiPatterns: ManagementProcess

AntiPatterns: Management

„^ Analysis Paralysis:

Striving for perfection and completeness

in the analysis phase leading to project gridlock and excessivework on requirements/modelswork on requirements/models. „ Death by Planning:

Excessive planning for software projects

leading to complex schedules that cause downstream problemsleading to complex schedules that cause downstream problems. „ Project Mismanagement:

Inattention to the management of

software development processes causing directionlessness andsoftware development processes causing directionlessness andother symptoms. Proper monitoring and control of softwareprojects is necessary.Department of Computer Engineering

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Sharif University of Technology

Software Development Methodologies – Lecture 19 Process AntiPatterns: Management –

Analysis Paralysis

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Analysis Paralysis:

Striving for perfection and completeness

„^ Analysis

Paralysis:

Striving

for perfection and completeness

in the analysis phase often leads to project gridlock andexcessive thrashing of requirements/models. „ Developers new to object-oriented methods do too much up-front analysis and design, using analysis modeling as anexercise to feel comfortable in the problem domainexercise to feel comfortable in the problem domain. „ A key indicator of Analysis Paralysis is that the analysisdocuments no longer make sense to the domain expertsdocuments no longer make sense to the domain experts. „ Solution:^

^ Iterative-incremental development processes that defer detailedanalysis until the knowledge is needed.Department of Computer Engineering

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Sharif University of Technology

Software Development Methodologies – Lecture 19 Process AntiPatterns: Management –

Project Mismanagement

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„^ Project Mismanagement:

Inattention to the management of

„^ Project

Mismanagement:

Inattention

to the management of

software development processes can cause directionlessness andother symptoms. „ Proper monitoring and control of software projects is necessary forsuccessful development activities.Oft^

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„^ Often, key activities are overlooked or minimized. These includetechnical planning (architecture) and quality-control activities(inspection and test). „^ Solution:^

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Proper risk management incorporated in the project managementprocess. Department of Computer Engineering

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Sharif University of Technology

Software Development Methodologies – Lecture 19 Reference „^ Brown, W. J., Malveau, R. C., McCormick, H., Mowbray, T.,Antipatterns: Refactoring Software, Architectures, andP^ j

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Projects in Crisis. Wiley, 1998.Department of Computer Engineering

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Sharif University of Technology