02
Sat, Nov
2 New Articles

Partner TechTip: Secrets Behind Enhancing RPG Applications

RPG
Typography
  • Smaller Small Medium Big Bigger
  • Default Helvetica Segoe Georgia Times

After measuring 12,000 projects, a leading researcher reveals his findings.

Written by Steve Kilner

Maintenance and enhancement projects for legacy systems are notorious for being budget busters and deadline killers. This article gives a quick overview of how you can significantly improve the success rate of such projects. For more information, you can also watch these short videos: Using Complexity Analysis to Lower Project Costs and Hyper-Navigation of RPG Systems.

Categorizing Maintenance Projects

In his epic book, Estimating Software Costs, Capers Jones describes four types of maintenance projects. These should be familiar to experienced maintenance developers and managers.

 

071111Kilner_types-of-maintenance-projects 

Figure 1: Maintenance projects can be divided into four types. (Click image to enlarge.)

Struggling Productivity (And a Breeding Ground for Defects)

It should come as no surprise that productivity of Type 4 projects is lower than Type 1 projects, which is lower still than greenfield projects. The statistics that have been gathered in this book show productivity to be 5-10 times lower for Type 4 projects than for Type 1. Also critical for software maintenance work is the fact that more complex projects are notorious for injecting new defects into existing systems.

A Prescription for Maintenance Productivity and Fewer Defects

The clear solution that Capers Jones offers to these problems—as a result of measuring over 12,000 actual software projects—is that improvements are readily obtained through the use of tools—in particular, static analysis tools and complexity analysis tools.

 

Let's look at these in more detail.

Static Analysis Tools: Faster, More Accurate Impact Analysis and Fewer Defects

Questions maintenance programmers must ask include:

 

  • What does this program do?
  • What programs reference this file or field?
  • Where do I need to change the code to produce the desired effect?
  • What will happen if I change this statement?

 

Answering these types of questions can be very time-consuming and error-prone. Mentally tracking the paths of fields through subroutines, programs, and files is a tedious exercise often derailed by interruptions and human limitations of concentration and memory. Fortunately, much of this activity can be automated through the use of a top-tier static analysis tool. For a quick view of how a static analysis tool can facilitate program analysis, see this video: Hyper-Navigation of RPG Systems.

 

As has been documented by numerous studies, maintenance programmers spend approximately half of their time trying to understand existing code. Providing tools that augment their mental tasks can significantly improve their throughput and quality.

Complexity Analysis Tools: Better Planning, Estimating, and Budgeting

How often have previously unknown complexities revealed themselves in mid-project, thereby seriously damaging your timelines and estimates? This is a common problem in software maintenance.

 

These hidden complexities can be discovered earlier through better analysis, as described above, but they can also be factored into the plan in a more holistic way by understanding the complexity of the targeted code through use of complexity analysis tools.

 

Complexity analysis, sometimes referred to as software metrics, can measure many aspects of software. For planning purposes, a manager is helped by understanding the degree of complexity of the programs being modified.

 

First, a quick explanation of complexity. These are the most common factors used to measure complexity in most languages, including RPG:

 

  • Quantity and depth of conditional logic
  • Total and unique counts of variables and operations
  • Amount of commenting available to the programmer
  • Numbers of statements in programs and subroutines

 

It is one thing to add, change, or delete 10 lines of code in a 50-statement program, but it's quite another to do the same thing in a 5,000-statement program. By understanding complexity measurements of the programs and subroutines being changed, the project manager can factor risk premiums into the project. Risk premiums can be applied to these tasks:

 

  • Completing program analysis
  • Design activities
  • Coding and unit testing
  • Test planning for scoping and preparation
  • QA and system testing execution

 

For a quick video demonstration of how to obtain complexity measurements for a project and factor them into a simple project spreadsheet, see Using Complexity Analysis to Lower Project Costs.

Overcoming the Challenge

To quote the man who has measured 12,000 software projects, Capers Jones, "Estimating the various forms of maintenance and enhancement work is among the most difficult problems facing software developers."

 

And he himself quotes 18th century wit, Samuel Johnson, who upon seeing a dog walk on its hind legs, said, "It is not done well, but it is surprising that it is done at all."

as/400, os/400, iseries, system i, i5/os, ibm i, power systems, 6.1, 7.1, V7, V6R1

Steve Kilner

Steve Kilner is a leading expert in the field of static analysis, software complexity metrics, and program comprehension. He is a specialist in the maintenance and migration of legacy software systems for the IBM i and has written extensively on the subject. As the founder of and current CEO of vLegaci, he developed a combination static and dynamic analysis tool for RPG. He currently leverages his experience through his partnership with Databorough, makers of X-Analysis.

BLOG COMMENTS POWERED BY DISQUS

LATEST COMMENTS

Support MC Press Online

$

Book Reviews

Resource Center

  • SB Profound WC 5536 Have you been wondering about Node.js? Our free Node.js Webinar Series takes you from total beginner to creating a fully-functional IBM i Node.js business application. You can find Part 1 here. In Part 2 of our free Node.js Webinar Series, Brian May teaches you the different tooling options available for writing code, debugging, and using Git for version control. Brian will briefly discuss the different tools available, and demonstrate his preferred setup for Node development on IBM i or any platform. Attend this webinar to learn:

  • SB Profound WP 5539More than ever, there is a demand for IT to deliver innovation. Your IBM i has been an essential part of your business operations for years. However, your organization may struggle to maintain the current system and implement new projects. The thousands of customers we've worked with and surveyed state that expectations regarding the digital footprint and vision of the company are not aligned with the current IT environment.

  • SB HelpSystems ROBOT Generic IBM announced the E1080 servers using the latest Power10 processor in September 2021. The most powerful processor from IBM to date, Power10 is designed to handle the demands of doing business in today’s high-tech atmosphere, including running cloud applications, supporting big data, and managing AI workloads. But what does Power10 mean for your data center? In this recorded webinar, IBMers Dan Sundt and Dylan Boday join IBM Power Champion Tom Huntington for a discussion on why Power10 technology is the right strategic investment if you run IBM i, AIX, or Linux. In this action-packed hour, Tom will share trends from the IBM i and AIX user communities while Dan and Dylan dive into the tech specs for key hardware, including:

  • Magic MarkTRY the one package that solves all your document design and printing challenges on all your platforms. Produce bar code labels, electronic forms, ad hoc reports, and RFID tags – without programming! MarkMagic is the only document design and print solution that combines report writing, WYSIWYG label and forms design, and conditional printing in one integrated product. Make sure your data survives when catastrophe hits. Request your trial now!  Request Now.

  • SB HelpSystems ROBOT GenericForms of ransomware has been around for over 30 years, and with more and more organizations suffering attacks each year, it continues to endure. What has made ransomware such a durable threat and what is the best way to combat it? In order to prevent ransomware, organizations must first understand how it works.

  • SB HelpSystems ROBOT GenericIT security is a top priority for businesses around the world, but most IBM i pros don’t know where to begin—and most cybersecurity experts don’t know IBM i. In this session, Robin Tatam explores the business impact of lax IBM i security, the top vulnerabilities putting IBM i at risk, and the steps you can take to protect your organization. If you’re looking to avoid unexpected downtime or corrupted data, you don’t want to miss this session.

  • SB HelpSystems ROBOT GenericCan you trust all of your users all of the time? A typical end user receives 16 malicious emails each month, but only 17 percent of these phishing campaigns are reported to IT. Once an attack is underway, most organizations won’t discover the breach until six months later. A staggering amount of damage can occur in that time. Despite these risks, 93 percent of organizations are leaving their IBM i systems vulnerable to cybercrime. In this on-demand webinar, IBM i security experts Robin Tatam and Sandi Moore will reveal:

  • FORTRA Disaster protection is vital to every business. Yet, it often consists of patched together procedures that are prone to error. From automatic backups to data encryption to media management, Robot automates the routine (yet often complex) tasks of iSeries backup and recovery, saving you time and money and making the process safer and more reliable. Automate your backups with the Robot Backup and Recovery Solution. Key features include:

  • FORTRAManaging messages on your IBM i can be more than a full-time job if you have to do it manually. Messages need a response and resources must be monitored—often over multiple systems and across platforms. How can you be sure you won’t miss important system events? Automate your message center with the Robot Message Management Solution. Key features include:

  • FORTRAThe thought of printing, distributing, and storing iSeries reports manually may reduce you to tears. Paper and labor costs associated with report generation can spiral out of control. Mountains of paper threaten to swamp your files. Robot automates report bursting, distribution, bundling, and archiving, and offers secure, selective online report viewing. Manage your reports with the Robot Report Management Solution. Key features include:

  • FORTRAFor over 30 years, Robot has been a leader in systems management for IBM i. With batch job creation and scheduling at its core, the Robot Job Scheduling Solution reduces the opportunity for human error and helps you maintain service levels, automating even the biggest, most complex runbooks. Manage your job schedule with the Robot Job Scheduling Solution. Key features include:

  • LANSA Business users want new applications now. Market and regulatory pressures require faster application updates and delivery into production. Your IBM i developers may be approaching retirement, and you see no sure way to fill their positions with experienced developers. In addition, you may be caught between maintaining your existing applications and the uncertainty of moving to something new.

  • LANSAWhen it comes to creating your business applications, there are hundreds of coding platforms and programming languages to choose from. These options range from very complex traditional programming languages to Low-Code platforms where sometimes no traditional coding experience is needed. Download our whitepaper, The Power of Writing Code in a Low-Code Solution, and:

  • LANSASupply Chain is becoming increasingly complex and unpredictable. From raw materials for manufacturing to food supply chains, the journey from source to production to delivery to consumers is marred with inefficiencies, manual processes, shortages, recalls, counterfeits, and scandals. In this webinar, we discuss how:

  • The MC Resource Centers bring you the widest selection of white papers, trial software, and on-demand webcasts for you to choose from. >> Review the list of White Papers, Trial Software or On-Demand Webcast at the MC Press Resource Center. >> Add the items to yru Cart and complet he checkout process and submit

  • Profound Logic Have you been wondering about Node.js? Our free Node.js Webinar Series takes you from total beginner to creating a fully-functional IBM i Node.js business application.

  • SB Profound WC 5536Join us for this hour-long webcast that will explore:

  • Fortra IT managers hoping to find new IBM i talent are discovering that the pool of experienced RPG programmers and operators or administrators with intimate knowledge of the operating system and the applications that run on it is small. This begs the question: How will you manage the platform that supports such a big part of your business? This guide offers strategies and software suggestions to help you plan IT staffing and resources and smooth the transition after your AS/400 talent retires. Read on to learn: