Home > Articles > Process Improvement

Like this article? We recommend

Technical Debt: A Primer

Why do we spend 80% of our software development budgets on software maintenance? Simply put: Despite our better instincts, it's still too easy to do the wrong thing when developing software. One example is the practice of "cut-and-paste coding." Suppose you have a sales compensation system that computes commissions. A batch process runs during each payroll to perform the commission calculation. This process sits in the payroll system, but somewhere else, perhaps in some commission dashboard that your salespeople use to see interim progress, you have the same commission calculation. As the business sponsor of the system, you signed off on this system after it was built initially. And why not? Technically, the system met its requirements—the commission calculation was correct (in both places).

The problem occurs when your commission structure changes. When someone comes along to change the system to accommodate the new commission structure, the code in at least two (and possibly more) unrelated areas needs to be changed. Worse, you have no reliable way of knowing whether all of those changes are right, without a full regression test of the system—if such a test is even possible!

In such a case, you have technical debt, defined as "the sum of future maintenance that could have been avoided if the software had been developed according to reasonable software-design practices." Cut-and-paste coding is just one way that technical debt is introduced. Designs that lack testability, inappropriate coupling, and dozens of other such practices contribute to this problem.

Why We Get Technical Debt

Like credit card debt, technical debt might "feel" good when we're in the process of accumulating it. We do things that optimize for the short term, but have a long-term expense that's far higher than the short-term gain we get—most of the time, as least. During the initial build of a system, it's easier to cut-and-paste logic from one module to another, rather than finding a way to reuse the logic. Technical debt usually comes from short-term optimizations of time without regard to the long-term effects of the change.

Interest Rate on Technical Debt

If the short-term optimizations that occur most of the time had a minor effect on maintenance (something like a 6% mortgage, say), such decisions to take on technical debt would be just fine. However, we frequently allow software development organizations to take out technical loans that, if they were transparent, would throw the corporate treasury department into a spiral of panic.

Let's look at our case study of the cut-and-paste code. The investment to do it right the first time is low (two days of work). In this case, you might write a shared module that does a commission calculation, making it available to any other module that needs such a calculation. Say we allow the development team to take out the "loan," and do cut-and-paste rather than spend the two days. In exchange for the two days of work, we'll incur future maintenance costs that are far higher. Making a conservative assumption, we'll say that we only did the cut-and-paste operation twice, resulting in the same calculation being in three places. Every time we change the commission structure in the future, we'll need to do the following:

  1. Find each instance where the commission calculation is performed—hoping that we got all of them (1 day)
  2. Make the change at each location—possibly customizing each change due to stylistic differences introduced by different developers (1 day each, 3 days total)
  3. Test each change, including performing regression tests to make sure that the change doesn't cause problems in seemingly unrelated places (1 day each, 3 days total)
  4. Put each change through the standard change-management process in multiple systems (0.5 days each, 1.5 days total)
  5. Discover that we missed one or two places, and repeat the process for each one we didn't find originally, upsetting the salespeople whose commissions were paid incorrectly (2.5 days minimum, plus an immeasurable amount of lost confidence)

At this point, we have 11 days of additional work invested every time we change the commission structure. Guessing conservatively, perhaps we only change the commission structure three times over 10 years (some places change it annually), we have net-interest payments of 33 days of effort, for which we were paid two days of effort up front.

The approach in this example results in a debt with an interest rate of about 32.4% (starting with two days of effort gained and paying it off with 33 days of effort lost over a 10-year period). I'm not a corporate policy expert, but my guess is that most accounting departments would balk at IT regularly taking out loans with interest rates like 32.4% that make loan sharks envious.

InformIT Promotional Mailings & Special Offers

I would like to receive exclusive offers and hear about products from InformIT and its family of brands. I can unsubscribe at any time.

Overview


Pearson Education, Inc., 221 River Street, Hoboken, New Jersey 07030, (Pearson) presents this site to provide information about products and services that can be purchased through this site.

This privacy notice provides an overview of our commitment to privacy and describes how we collect, protect, use and share personal information collected through this site. Please note that other Pearson websites and online products and services have their own separate privacy policies.

Collection and Use of Information


To conduct business and deliver products and services, Pearson collects and uses personal information in several ways in connection with this site, including:

Questions and Inquiries

For inquiries and questions, we collect the inquiry or question, together with name, contact details (email address, phone number and mailing address) and any other additional information voluntarily submitted to us through a Contact Us form or an email. We use this information to address the inquiry and respond to the question.

Online Store

For orders and purchases placed through our online store on this site, we collect order details, name, institution name and address (if applicable), email address, phone number, shipping and billing addresses, credit/debit card information, shipping options and any instructions. We use this information to complete transactions, fulfill orders, communicate with individuals placing orders or visiting the online store, and for related purposes.

Surveys

Pearson may offer opportunities to provide feedback or participate in surveys, including surveys evaluating Pearson products, services or sites. Participation is voluntary. Pearson collects information requested in the survey questions and uses the information to evaluate, support, maintain and improve products, services or sites, develop new products and services, conduct educational research and for other purposes specified in the survey.

Contests and Drawings

Occasionally, we may sponsor a contest or drawing. Participation is optional. Pearson collects name, contact information and other information specified on the entry form for the contest or drawing to conduct the contest or drawing. Pearson may collect additional personal information from the winners of a contest or drawing in order to award the prize and for tax reporting purposes, as required by law.

Newsletters

If you have elected to receive email newsletters or promotional mailings and special offers but want to unsubscribe, simply email information@informit.com.

Service Announcements

On rare occasions it is necessary to send out a strictly service related announcement. For instance, if our service is temporarily suspended for maintenance we might send users an email. Generally, users may not opt-out of these communications, though they can deactivate their account information. However, these communications are not promotional in nature.

Customer Service

We communicate with users on a regular basis to provide requested services and in regard to issues relating to their account we reply via email or phone in accordance with the users' wishes when a user submits their information through our Contact Us form.

Other Collection and Use of Information


Application and System Logs

Pearson automatically collects log data to help ensure the delivery, availability and security of this site. Log data may include technical information about how a user or visitor connected to this site, such as browser type, type of computer/device, operating system, internet service provider and IP address. We use this information for support purposes and to monitor the health of the site, identify problems, improve service, detect unauthorized access and fraudulent activity, prevent and respond to security incidents and appropriately scale computing resources.

Web Analytics

Pearson may use third party web trend analytical services, including Google Analytics, to collect visitor information, such as IP addresses, browser types, referring pages, pages visited and time spent on a particular site. While these analytical services collect and report information on an anonymous basis, they may use cookies to gather web trend information. The information gathered may enable Pearson (but not the third party web trend services) to link information with application and system log data. Pearson uses this information for system administration and to identify problems, improve service, detect unauthorized access and fraudulent activity, prevent and respond to security incidents, appropriately scale computing resources and otherwise support and deliver this site and its services.

Cookies and Related Technologies

This site uses cookies and similar technologies to personalize content, measure traffic patterns, control security, track use and access of information on this site, and provide interest-based messages and advertising. Users can manage and block the use of cookies through their browser. Disabling or blocking certain cookies may limit the functionality of this site.

Do Not Track

This site currently does not respond to Do Not Track signals.

Security


Pearson uses appropriate physical, administrative and technical security measures to protect personal information from unauthorized access, use and disclosure.

Children


This site is not directed to children under the age of 13.

Marketing


Pearson may send or direct marketing communications to users, provided that

  • Pearson will not use personal information collected or processed as a K-12 school service provider for the purpose of directed or targeted advertising.
  • Such marketing is consistent with applicable law and Pearson's legal obligations.
  • Pearson will not knowingly direct or send marketing communications to an individual who has expressed a preference not to receive marketing.
  • Where required by applicable law, express or implied consent to marketing exists and has not been withdrawn.

Pearson may provide personal information to a third party service provider on a restricted basis to provide marketing solely on behalf of Pearson or an affiliate or customer for whom Pearson is a service provider. Marketing preferences may be changed at any time.

Correcting/Updating Personal Information


If a user's personally identifiable information changes (such as your postal address or email address), we provide a way to correct or update that user's personal data provided to us. This can be done on the Account page. If a user no longer desires our service and desires to delete his or her account, please contact us at customer-service@informit.com and we will process the deletion of a user's account.

Choice/Opt-out


Users can always make an informed choice as to whether they should proceed with certain services offered by InformIT. If you choose to remove yourself from our mailing list(s) simply visit the following page and uncheck any communication you no longer want to receive: www.informit.com/u.aspx.

Sale of Personal Information


Pearson does not rent or sell personal information in exchange for any payment of money.

While Pearson does not sell personal information, as defined in Nevada law, Nevada residents may email a request for no sale of their personal information to NevadaDesignatedRequest@pearson.com.

Supplemental Privacy Statement for California Residents


California residents should read our Supplemental privacy statement for California residents in conjunction with this Privacy Notice. The Supplemental privacy statement for California residents explains Pearson's commitment to comply with California law and applies to personal information of California residents collected in connection with this site and the Services.

Sharing and Disclosure


Pearson may disclose personal information, as follows:

  • As required by law.
  • With the consent of the individual (or their parent, if the individual is a minor)
  • In response to a subpoena, court order or legal process, to the extent permitted or required by law
  • To protect the security and safety of individuals, data, assets and systems, consistent with applicable law
  • In connection the sale, joint venture or other transfer of some or all of its company or assets, subject to the provisions of this Privacy Notice
  • To investigate or address actual or suspected fraud or other illegal activities
  • To exercise its legal rights, including enforcement of the Terms of Use for this site or another contract
  • To affiliated Pearson companies and other companies and organizations who perform work for Pearson and are obligated to protect the privacy of personal information consistent with this Privacy Notice
  • To a school, organization, company or government agency, where Pearson collects or processes the personal information in a school setting or on behalf of such organization, company or government agency.

Links


This web site contains links to other sites. Please be aware that we are not responsible for the privacy practices of such other sites. We encourage our users to be aware when they leave our site and to read the privacy statements of each and every web site that collects Personal Information. This privacy statement applies solely to information collected by this web site.

Requests and Contact


Please contact us about this Privacy Notice or if you have any requests or questions relating to the privacy of your personal information.

Changes to this Privacy Notice


We may revise this Privacy Notice through an updated posting. We will identify the effective date of the revision in the posting. Often, updates are made to provide greater clarity or to comply with changes in regulatory requirements. If the updates involve material changes to the collection, protection, use or disclosure of Personal Information, Pearson will provide notice of the change through a conspicuous notice on this site or other appropriate way. Continued use of the site after the effective date of a posted revision evidences acceptance. Please contact us if you have questions or concerns about the Privacy Notice or any objection to any revisions.

Last Update: November 17, 2020