Home > Articles > Software Development & Management

Using Function Points Effectively

This article describes common uses of the function point metric by the software development organization. To demonstrate the versatility of the function point metric, we have selected two scenarios; each represents the use of the metric at a different level in the organization. Function points are used at the IT management level as the key normalizing metric in establishing performance benchmarks used to identify and track improvements. Second, function points are often used at the organizational level as the base metric for establishing quantifiable service levels (seen primarily in outsourcing arrangements).

This article describes common uses of the function point metric by the software development organization. To demonstrate the versatility of the function point metric, we have selected two scenarios; each represents the use of the metric at a different level in the organization. Function points are used at the IT management level as the key normalizing metric in establishing performance benchmarks used to identify and track improvements. Second, function points are often used at the organizational level as the base metric for establishing quantifiable service levels (seen primarily in outsourcing arrangements).

In each of the two scenarios, function point analysis has its greatest value when used in conjunction with other metrics. For example, simply knowing the average size of your software deliverable (expressed in function points) is of little value; however, by incorporating other data points, such as deliverable cost, duration, and defects, you can create and report on value-added measures such as the cost per function point, time to market, and defect density.

It is true that the function point metric is not a panacea for software development ills; however, it does afford the development team and IT management an opportunity to measure and evaluate key elements in the development environment to make more informed decisions.

IT Management Level: Establishing Performance Benchmarks

Baselining an organization's performance level has become a standard industry practice, particularly in companies whose IT organizations are required to track and improve their delivery of products and services relative to improved time to market, cost reduction, and customer satisfaction. Creation of an IT performance baseline (often referred to as benchmarking) gives an organization the information it needs to properly direct its improvement initiatives and mark progress.

Performance levels are commonly discussed in terms of delivery—for example, productivity, quality, cost, and effort. In each of these categories, function points are used as the denominator in the metrics equation. By using function points as the base measure, the organization benefits in two ways. First, because function points are applied in a consistent and logical (not physical) fashion, they are considered a normalizing metric, thus allowing for comparisons across technologies, across business divisions, and across organizations, all on a level playing field. Second, there is an extraordinary amount of industry baseline data, which can be used to compare performance levels among various technologies and industries and to compare internal baseline levels of performance to best-practice performance levels.

Noted in Table 1 are some examples of industry data points for productivity levels. The values are expressed in hours per function point as a rate of delivery. These data points are from the International Software Benchmarking Standards Group (ISBSG), one of the numerous sources of industry benchmark data. The ISBSG data displayed in Table 2 depicts similar rates by business area.

Table 1

ISBSG Industry Data

Function Point Size



Packaged Software



























Note: All values are expressed in hours per function point as a rate of delivery.

Table 2

Rates of Delivery by Business Area

Business Area

Rate of Deliverya













aExpressed in hours per function point.

The data points shown in tables 1 and 2 make obvious the advantage of using function points. Representative industry performance data using function point-based measures and data points is available for organizations to use as the basis of their cost and performance comparisons to industry averages and best practices.

For an organization that has been engaged in the collection and analysis of its own metrics data, creating baseline information similar to the industry views displayed in tables 1 and 2 is a relatively easy task. However, most organizations do not have the advantage of readily available metrics data; therefore, they need to create a baseline of performance data from the ground up. Fortunately, a baseline can be developed relatively economically, depending on the level of systems documentation and project management data available.

The baselining process includes the quantifiable measurement of productivity and quality levels. Performance is determined according to measurements collected from a representative sampling of projects. The selection of projects is commonly based on unique criteria:

  • The project was completed or was undergoing development during the previous 18 months.

  • The labor effort to complete the project amounted to more than six staff-months.

  • The project represents similar types of projects planned for future development.

  • The primary technical platforms are represented.

  • The project selection includes a mix of technologies and languages.

Project data is collected (when available) on the function point size of the deliverable, level of effort, project duration, and number of defects. These measures are analyzed, and performance levels are established on a project-by-project basis. These data points can then be used to create a quantitative baseline of performance (see Figure 1). In Figure 1, data points for all projects are recorded during the baselining process. These data points create one view of an organizational baseline. The data points include an expression of functional size and rate of delivery. For our purposes, rate of delivery is expressed in terms of function points per person-month.

Figure 1

Rate of delivery during baselining

Figures 2 and 3 have sorted the baseline projects relative to the type of development. Figure 2 shows all enhancement projects; Figure 3 shows all new development projects. Note the difference among the various views for a baseline project of 400 function points. The advantage of looking at this baseline data from different viewpoints is to better understand the impact of different development types on performance levels. It would not be reasonable to expect future enhancement projects to perform at the same rate of delivery as new development projects.

Figure 2

Rate of delivery for enhancement projects

Figure 3

Rate of delivery for new development projects

Obviously, project size and complexity are contributing factors that influence productivity. However, numerous other factors also affect the capacity of an organization to define, develop, and deploy software. Assessing an organization's capacity to deliver represents the qualitative portion of the benchmarking process. A capacity analysis reveals the influence of current software practices on performance levels. Using the information from the capacity analysis, it is possible to recommend improvements in current practices, to suggest new practices, and to emphasize existing practices that have already demonstrated positive influence on productivity.

For example, we can observe from figures 1 through 3 that our capacity to deliver is influenced by size and type of development. If we hold these two variables constant while analyzing our baseline data, we can observe that there are still variations in performance data.

Figure 4 shows data from several projects that are closely related in size. Four data points fall in the range of 400 to 550 function points. Their corresponding rates of delivery are from 8 to 18 function points per person-month. That is a significant difference in performance. The challenge now becomes one of determining the contributing factors that caused these projects to perform at different levels.

Figure 4

Rate of delivery by functional size

We have completed many of these types of process performance assessments on the basis of our own proprietary assessment method. The method of collection consists of selected interview and team survey sessions with each of the project teams. Data is collected on key influence factors, such as project management capabilities, requirements and design effectiveness, build and test practices, skill levels, and other contributing environmental factors. Individual projects are analyzed, and project profiles are created. This data is also analyzed in aggregate and may be used as the basis for determining overall organization process improvements.

The results are somewhat predictable. Typical influence factors include skill levels, effective use of front-end life cycle quality practices, tool utilization, and project management. These findings parallel, in part, those of the ISBSG database analysis, which revealed that language complexity, development platform, methodology, and application type were significant factors influencing productivity.

Analysis of the qualitative data leads an organization to the discovery of certain process strengths and weaknesses. As performance profiles are developed and contrasted with quantitative levels of performance, key software practices that are present in the higher-performing projects tend to be missing from the lower-performing projects. These practices differentiate between success and failure.

The real value of the benchmarking activity results from identifying performance levels, analyzing process strengths and weaknesses, monitoring process improvements, and comparing to industry data points. There is much to be learned from comparisons to industry data. An IT organization can see at a glance the overall effectiveness of its performance in contrast to industry benchmarks. In addition, there is an opportunity to identify industry best practices and to evaluate how these best practices will affect your organization's performance levels.

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.


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.


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.


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.


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


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


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.


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.


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