Practical Software Estimation Measurement

Blogs

The Lowly Line of Code (Part One)

“I'm sorry, Dave. I'm afraid I can't do that” – HAL 9000[1]

Source lines of code (SLOC) is a measure of software size, in use since the 1960s. This blog post describes various uses of SLOC from the perspective of software measurement.

There seems to be a love/hate relationship with the line of code measure. Despite its broad and continuous use (or perhaps because of it) SLOC seems to get the blame for many a failed software project, process improvement or software metrics initiative. There are even those who claim that “…in many situations usage of LOC metrics can be viewed as professional malpractice…”[2] But, as you will see, SLOC has many benefits, when used intelligently.

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Metrics Sizing Software Sizing

Should Task Planning Occur Before Software Estimation?

I work for QSM, a leading software project estimation and demand management company. We focus on top-down estimation, meaning we figure out the total project duration and effort before any detailed planning occurs. We use SLIM-Estimate also known as the Putnam Model. Larry Putnam Sr. introduced SLIM in 1978. It is one of the leading software estimation tools in the world, validated with over 35 years of industry leading research and updated regularly with the latest technologies. 

Many people call us for help with team size software project estimation, they want to see how many people it’s going to take to deliver a specified amount of functionality within a certain duration and budget. At the time they call us they are often using task level planning tools to try to figure this out. 

The problem is that it’s tough to allocate people and the number of hours they will work when they haven’t figured out the specific requirements of each task and when they haven’t estimated the total duration and effort for the overall system. A manager could spend days creating a task level plan that doesn’t add up to the overall project duration and budget that is needed to deliver the functional requirements. When it doesn’t add up then re-planning has to take place costing more time and money. This is why QSM recommends estimating the big picture first, the scope level. 

Blog Post Categories 
Estimation Process Improvement Sizing

ITMPI Webinar - Agile Estimation: Beyond the Myths

Presented by for ITMPI on Sept. 9 at 11:00 AM EST by Dr. Andy Berner.

When it comes to agile, there are common myths and misconceptions about estimation. In this webinar, QSM’s Andy Berner will offer corrections to these, such as:

  • Why we still need to estimate duration on agile projects
  • Why velocity is not constant on a project, or across projects
  • Why setting expectations based on scope is still important, even as we “embrace change”
  • Why burndown charts will not be straight lines
  • Why you still need to plan for work on requirements, even though it’s not all “upfront”

While some longstanding principles about software estimation still apply, agile methods require some significant changes to how we estimate. This webinar will show you how to tailor estimation tools and methods specifically to an agile development environment to estimate, measure, and analyze your agile software development projects. Andy Berner will demonstrate how top-down estimation fits with the principles of agile development, and will discuss what needs to be estimated, how size factors in, and how to accommodate different iteration lengths and types of work. This will allow you to optimize the choices and plans for the work of your agile teams.

Register for this webinar!

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Agile Webinars

How Cyber Secure Is the Software in Your Car?

Cyber Security JeepThis past July marked the first cyber security recall in automotive history.  Fiat Chrysler issued a formal voluntary recall of 1.4 million vehicles after security researchers Charlie Miller and Chris Valasek demonstrated to WIRED how they could exploit a software vulnerability in Chrysler’s Uconnect dashboard computers and remotely hack into a 2014 Jeep Grand Cherokee over the Internet, taking over dashboard functions, transmission, steering and brakes.  Most notably, they did so from their basement while WIRED author Andy Greenberg was driving the vehicle on the highway!

Though this was first time an automotive manufacturer issued a recall for cyber security, it’s not the first time security risks have been found in automotive software.  As I’ve pointed out in my previous article “How Much Software Is in Your Car?” nearly every vehicle less than 30 years old on the road today depends on lots of computer software and thus is potentially vulnerable to hacking, especially newer models that are connected to the Internet.  

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Cyber Security Program Management

New Article - 10 Steps to Better Metrics

10 Steps to Better Metrics

An effective software measurement program is a long-term investment, not a quick fix. In this article originally published in Projects at Work, Carol Dekkers identifies 10 steps to ensure your organization's metrics deliver a positive return on that investment, from more accurate cost and schedule estimation, to streamlined processes and better insights into current and future commitments.

Read the full article!

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Metrics Articles

New Book - Understanding Software Estimation, Negotiation, and Demand Management: An Executive Primer

Understanding Software Estimation, Negotiation, and Enterprise Demand Management: An Executive Primer

QSM is pleased to announce the release of a new book, Understanding Software Estimation, Negotiation, and Demand Management: An Executive Primer. Historically, only 20% of software projects are completed successfully and with software becoming critical to nearly every company and industry, having such a high rate of failure is simply unacceptable anymore. It is for this reason that QSM has compiled this collection of articles that will aid anyone from project managers to CIOs in implementing software estimation, negotiation and demand management methods efficiently to reduce costs.

Larry Putnam, Sr., founder of QSM and a pioneer and top problem solver in the software estimation and measurement field, provides the foreword to the book, which is co-authored by his son and granddaughter, Doug Putnam and Taylor Putnam-Majarian. Combined, the authors bring more than 40 years of experience in software measurement to a range of topics, including:

Averages Considered Harmful

Arithmetic mean (aka average) is often a misleading number. One reason for this is that mean is sensitive to outliers. A very large or a very small value can greatly influence the average. In those situations a better measure of center is the median (the 50th percentile). But there is a second huge pitfall awaiting anyone using average for estimating or benchmarking: software size.

Even though we know that software size has a major influence on the key metrics (e.g., effort, duration, productivity, defects) many people insist on reporting and comparing and using the average value. Let’s look at an example. Consider a sample of 45 completed telecommunications application type projects. Picking one of the key metrics already mentioned, duration of phase 3, we can generate a histogram and calculate the mean. The average duration is 27.5 months. Does this tell us anything useful?

Number of Software Projects vs. Duration

The histogram of durations shows a skewed distribution (many projects have a shorter duration, few have a long duration), so we will need to do some sort of normalization before the average is a measure of center.  And even then, what about size?  In a typical SLIM scatterplot of duration versus size for these projects, we can see that in general larger projects take longer than smaller ones.  

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Software Sizing

Webinar Replay - What's New in SLIM-Suite 9.0

SLIM-Suite 9.0

A foundation of the SLIM philosophy is to know what your team is capable of producing and never promise to deliver more than those finite limits. Leveraging a history of completed project core metrics enables you to quantify your capabilities, and not only provide a defensible basis of estimation, but support statistical analysis for project benchmarking and identifying performance improvement opportunities.

QSM's newest release of SLIM-Suite, version 9.0, provides a number of enhancements to simplify and organize completed project data in SLIM-DataManager and manage data set definitions and queries in SLIM-Metrics. In this webinar, Laura Zuber demonstrates key new features of both products. You will see how providing project size details, master keyword lists, multiple view layouts, and multi-select variable analysis equip you to expand your historical project repository and increase its use.

Watch the replay!

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Webinars SLIM Suite

New Article: An Updated Software Almanac

Industry expert Phillip Armour highlights the importance of the QSM Software Almanac: 2014 Research Edition in his recent article for Communications of the ACM.

Software projects can be so complicated and so different from each other that predicting whether they will succeed or fail can be as difficult as forecasting the weather or picking winning stocks. Will the project entirely fulfill its goals? Will it deliver some value at a higher cost or later than desired? Or will it just crash and burn leaving the exhausted survivors to lick their wounds, bury the dead bodies, and shred the evidence?

Courageous efforts are being made to collect and codify the data that is available, to try to spot what trends are occurring in the industry, and to provide some useful guidelines for managing the business of software. The recently published QSM Software Almanac, dubbed the "2014 Research Edition," is an example of this.

Read the full article!

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QSM News Articles

New Article: Full-Circle Estimating

 Full-Circle Estimating

While creating estimates is a fundamental step toward improving productivity on software development projects, it is not enough. In "Full-Circle Estimating," recently published on Projects at Work, Doug Putnam and Taylor Putnam-Majarian present a full-circle model that organizations can apply to track actual performance against estimates, reforecast when significant changes occur, and then continually refine the process through post-mortem assessment.

Doug Putnam is co-CEO for Quantitative Software Management (QSM). He has 35 years of experience in the software measurement field and has been instrumental in the development of the SLIM Suite of software estimation and measurement tools. C. Taylor Putnam-Majarian is a consulting analyst at QSM with over seven years of specialized data analysis, testing and research experience. In addition to providing consulting support in software estimation and benchmarking engagements to clients from both the commercial and government sectors, Taylor has authored numerous publications about Agile development, software estimation and process improvement.

Read the full article!

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Estimation Articles