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INFO 631 Prof. Glenn Booker

Week 6 – Tools and Review

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Overview

• This week examines software development tools, both for support of technical aspects of development and maintenance as well as management concerns

• We’ll wrap up with a summary of software-related metrics

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Tools

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Scope

• Tools (e.g. software applications) to support the development and maintenance of software cover a wide range of purposes, from very specific to nearly all-encompassing– Some focus on the technical development

activities (the development life cycle)– Others focus on support activities (project

management, CM, etc.)

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CASE Tools

• The first tools for managing the software development process were called CASE tools (e.g. Computer-Aided Software Development)– Upper CASE tools support the earlier parts

of development – concept definition, requirements analysis, early design

– Lower CASE tools support implementation and testing

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CASE Tools

• The CASE Tools terminology is a bit dated, but you’ll still see it here and there

• A classic CASE tool (both upper and lower) is IBM’s Rational tool suite– The key idea is to have a set of applications

that can capture requirements for a system, map them into design drawings, implement those designs in code, and automate the testing of that code

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Visual Studio

• A major player is Microsoft’s Visual Studio, which can handle many functions, depending on which version you get:– Architecture and modeling– Database development– IDE, debugging and diagnostics– Testing tools– Lab management

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Compilers and IDEs

• A compiler turns source code into object files, which are linked to produce an executable application (e.g. MSWord.exe)

• An Integrated Development Environment (IDE) goes beyond that to help manage the source code for a project, and possibly automate testing– The line between IDE and lower CASE tool

gets pretty fuzzy!INFO631 Week 6 8

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Support tools

• Other tools provide support for the development process, such as tools for– Project management– Risk management – Configuration management– Change management

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Project management

• Project management tools support the definition of project tasks, assigning resources to them, tracking project costs, and monitoring project progress

• Sadly, MS Project is the most common tool for this purpose– Not particularly good, it just has lots of market

share to wipe out competition

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Project management

• Major categories of activities include– Project planning– Resource planning– Project tracking, analysis, and reporting– Project collaboration

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Risk management

• Risk management tools support the four major risk management activities– Risk identification; identify what risks might

realistically affect your project– Risk analysis; assess each risk, determine its

probability and likely impact on the project– Risk response planning; what will you do if the

risk occurs?

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Risk management – Risk monitoring and control; how do you

manage each risk after it has occurred?• There are many commercial tools for risk

management– I haven’t seen any widely used– Many RM tools are developed in-house

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Configuration management

• Configuration management (CM) tools support the four major areas of CM– Configuration identification; what stuff are you

tracking, and how?– Configuration control; fits with change control

processes– Configuration audits; do you really have what

you think you have?– Configuration reporting; status updates

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Configuration management

• CM tools help manage the detailed complexity of keeping track of all the stuff in your project– Many involve SCM (software CM) or VCS

(version control system) in their names

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Change management

• Closely related to CM, change management is the process of controlling the evolution of your product– Inputs to change control include problem

reports (bugs) as well as new features– The process determines which bugs are fixed,

and features implemented– Changes are tracked through their inclusion

in a new baseline version of your system

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Change management

• Change management tools provide support for identification of proposed changes, analyzing them, and tracking them through implementation– Many of these tools are developed in-house

to meet specific project needs and workflow processes

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Tools and measurement

• So how does this connect to measurement?– Tools can be measured in terms of their costs

and benefits to the project• What costs are involved?

– Purchase cost– Maintenance cost– Training costs– Reduced productivity during implementation

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Tools and measurement

• Do we use the tools?– Measure tool usage – how many people? – How many modules/risks/changes/tasks/etc.

are being managed with the tools?• How do they benefit the organization?

– Hmm, how could you measure benefits for tools?

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Tool Metrics• Recall some basic tool metrics from INFO 630:

– How much (time, labor effort, cost) did our tools cost? Does that include training?

– How much are the tools being used?– Are the tools meeting our needs?– Are they providing unexpected benefits?– How has use of the tools affected our productivity?

Rework? Defect rate?• What do we have to do before and after

implementing new tools to measure these things?

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Review

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Software Measurement Overview

• We have studied the kinds of measurement methods and characteristics needed for software development and maintenance– We’ve used SPSS to do the icky math parts

for us, and emphasized understanding what kinds of techniques are used, and how to interpret their results

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Life Cycle Model

• Most of our concepts are based on some variation of the key software development activities– Requirements analysis– High and low level design– Coding or implementation– Various levels of testing

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Motivation

• Measurement is critical from a project management perspective, to give us an objective basis for making decisions and answering questions

• It also helps fulfill objectives of various quality and process models (CMMI, ISO 9000, etc.)

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Foundation

• We defined measurements for each aspect of a process– The product we create– The resources (people) we use to create it– The processes they follow– The tools they use

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Statistical Concepts• Key statistical concepts used include

– Measurement scales (nominal, etc.)– Ratio, proportion, fraction, percent, and rate– Modeling to see if there’s a statistically

significant relationship between two measures• And assess R squared and the T statistic to help

make that judgment

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Normal Distribution

• We reviewed the normal distribution– The 95% rule for deciding how close to the

mean is ‘close enough’ to be important– Six Sigma

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Core Measurements

• The most common foundation for measurement is– Product Size (LOC or function points)– Effort and cost– Schedule– Problems and defects, including the defect

density (defects/KLOC)

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Development and Defect Models

• We considered development models to relate various key measures to each other (COCOMO)

• And examined defect removal effectiveness

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Quality Management

• We looked at key aspects of a Quality Management System and key development and maintenance metrics often used– Defect arrival rate– Fix backlog– Fix response time– Etc.

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Earned Value• We looked to the earned value method for

comparing the effort, schedule, and work accomplished during a project– ACWP, BCWP, BCWS, CPI, SPI

• If you still remember what they mean, you deserve a cookie!

– Cost and schedule variances, schedule slip, estimate at completion

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GQ(I)M

• We used the goal, question, indicator, and measure methodology to: – Help understand why we are collecting the

measures– Define exactly what they mean– Where they come from– How they will be presented (the indicators)

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Defect Analysis

• Defect analysis looked at:– When a defect was created (“injected”)– When a defect was found (“detection”)– What caused a defect (type of defect, and/or

orthogonal defect classification)– How a defect was found (triggers)

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Defect Removal Modeling

• Defect removal modeling defined the defect removal effectiveness (DRE) for any set of adjacent life cycle phases

• Then the Rayleigh model provided a mathematical expression to help predict how many more defects will be found during development

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Reliability Modeling

• Static reliability models provide a detailed estimate of defects per module based on size and complexity metrics

• Dynamic reliability models provide a broader estimate of the defects in the entire project, such as the Rayleigh model (from the Weibull model)

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Reliability Modeling

• Lots of other types of reliability models were covered briefly– Exponential model for testing– Time Between Failure Models – Fault Count Models– Time Between Failures

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Customer Satisfaction

• We discussed ways of conducting Customer Satisfaction Surveys– Statistical sampling methods– How to calculate simple random sample size

• Analysis of customer satisfaction data

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Testing Measurements

• We discussed approaches to testing• Testing measurements beyond just defects

found• Structural and predicate testing• Integration testing strategies

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Object Oriented Measures

• We covered six common OO metrics– Weighted methods per class (WMC)– Response for a class (RFC)– Lack of cohesion of methods (LCOM)– Coupling between objects (CBO)– Depth of inheritance tree (DIT)– Number of children (NOC)

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Complexity Metrics

• We examined internal and external complexity metrics– Internal – size, the Halstead metrics,

cyclomatic complexity, knots– External – data structure, fan in, fan out,

Henry and Kafura, Shepperd• And looked at availability metrics

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Quality Assessment and Audit

• We looked at quality assessments and quality audits, and their common structure– Preparation phase– Evaluation phase– Summarization phase

• And examined the larger view of the Process Assessment Cycle

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CMMI Structure

• We reviewed the structure of the CMMI process model– Staged versus continuous models– Process Areas and their goals

• And examined the role of software development and management tools

• And that’s it!