Estimating the Time Required for Business Rules Harvesting — Part 2: Provide the Estimate

Gladys S.W.  Lam
Gladys S.W. Lam Co-Founder & Principal, Business Rule Solutions, LLC , Publisher, Business Rules Journal and Executive Director, Building Business Capability (BBC) Read Author Bio       || Read All Articles by Gladys S.W. Lam

In Part 1 of this series, I provided 13 questions you must ask before estimating the time required for your business rules harvesting effort.  With that information in hand, you can now carry on with your estimate.  Given below is a guiding formula that I use to establish a baseline estimate of the project time required, based on my proposed number of minutes required per business rule.  Use the answers to your 13 questions to then adjust the estimate as needed.

However, before jumping into heavy business rules harvesting activities, there is some preliminary work that you need to do.  In fact, this pre-work is crucial to the success of your effort. 

Allow 1-2 weeks to:

  • develop a business vocabulary model[1]
  • develop a decision structure[2]
  • define a process model[2]

Now, let's proceed with the baseline formula:

      Baseline average time per business rule = 45 minutes       

These 45 minutes include:

  • specification of the business rule into business rule statements,
  • analysis of the business rule set for conflict, duplication, or gaps,
  • setting up of some basic traceability elements, and
  • two external reviews.

Next, adjust your estimate by the following:


Your answer can be:


  1. What are your objectives for business rules harvesting?
  • Ongoing business rules management by the business

  • System implementation

  • Both

The baseline assumption is Ongoing business rules management by the business.

If your answer is either System Implementation or Both, you can actually reduce the estimate.  You save time by not having to organize your business rules for ongoing management.
  1. What types of business rules?
  • Decision rules

  • Behavioral rules

The baseline assumption is Decision Rules.

If your answer is Behavioral Rules, you might need to add more time.  This is because Behavioral Rules are often not documented.  They are in people's heads, and different people might have different ideas for a given rule. 

The good news is that the number of Behavioral Rules is likely to be a lot less than the number of Decision Rules for a given scope.  The total amount of time for harvesting a set of Behavioral Rules is likely to be less than the total amount of time needed to harvest a set of Decision Rules.
  1. What is the availability of subject area knowledge and expertise?
  • Subject area expertise is available

  • Subject area expertise is not readily available

The baseline assumption is that subject area experts are available and that subject area experts are familiar with the scoped business area.

Naturally, more time would be required if a subject area expert is not available and is not familiar with the business.
  1. How understandable is the source material?
  • Understandable

  • Not easily understood

The baseline assumption is that the source materials can be understood directly (i.e., in 1 or 2 readings) without a lot of explanation from subject area experts.

More time would be required if the source materials need a lot of explanation from subject area experts.
  1. How many business rules?
  • By Process tasks/activities

  • By Decision

The baseline assumption is 800-1000 decision rules or 400-500 behavioral rules.

Having more business rules would mean more relationships between the rules and therefore more analysis.  More time would be needed.

A smaller number of rules would mean less time per rule.
  1. Does the scoped area use consistent terminology?
  • Yes

  • Not always

Terminology is the backbone of business rules.  The baseline assumption is that the scoped area uses consistent terminology and that the stakeholders of the area know the importance of consistent terminology usage.

More time would be required if the scoped area needs to be educated on the importance of vocabulary.
  1. Is there already a terminology model?
  • Yes

  • No

An already-approved terminology model can save a lot of time on business rules specification.

The assumption is that there is no terminology model.  Less time would be required if a terminology model exists that covers more than 70% of the vocabulary used in the business rules.
  1. What is the level of rule harvesting experience of business (rules) analyst(s)?
  • Has harvested business rules for 2 projects or more

  • Has been trained but has not conducted any project work

  • Has not been trained

The assumption is that the business (rule) analysts already have experience in harvesting business rules for 2 or more projects.

More time would be required if the business (rule) analysts do not have the necessary training or experience.
  1. How many external review cycles?
  • More than 2 review cycles

  • 2 review cycles

  • Fewer than 2 review cycles

The baseline assumption includes 2 external review cycles.

More external reviews would mean more time required.

Fewer external reviews might not be wise.
  1. What are the traceability requirements for business rule management?
  • Do not need to manage any information about the business rules

  • Manage basic 3-5 elements

  • Manage more than 5 elements

The baseline assumption is 3-5 traceability elements.

More traceability elements would mean more time to collect and maintain information.
  1. How complex are the business rules?
  • Low complexity

  • Medium complexity

  • High complexity

The baseline assumption is medium complexity of the entire rule set.  It is expected that some rules might be very simple and some are highly complex.

If most business rules are simple, then less time.

If most business rules are highly complex, then more time.
  1. Do the business rules need to be re-engineered?
  • Yes

  • No

The baseline assumption is harvesting one set of business rules.

If you need to harvest the 'as-is' business rules and then re-engineer them as 'to-be' business rules, you will need more time since there are going to be more and different business rules resulting from the re-engineering effort.
  1. What tools will be used?
  • Office suite (e.g., Microsoft)

  • Specialized tool for business rules management

  • Enterprise architecture tool

  • Rules Engine

The assumption is that you have some basic tool to help you with capturing, analyzing, organizing, and reporting on business rules.

Expect more time will be required if you have inadequate tool support.

Some automated tools allow you to go from capture, to analysis, to implementation very quickly.  The emphasis is still on the correct specification of the business rule logic.

Veronica O'Grady from New Zealand's Inland Revenue Department has documented how they were able to implement 3500 pages of tax law in 12 months — an incredible success story for using the business rules approach.[3]

Just Remember…

Plainly speaking, here are some of the main things you need to remember:

  • The baseline time estimate provided depends heavily on answers to the 13 key questions provided in Part 1 of the series.

  • An automated tool can help with analysis, management, testing and implementation of the business rules and decisions; however, the harvesting and specification of the correct business logic is still in the hands of a good business (rule) analyst.

  • It is not about how many business rules and decisions you can capture and implement in how short a time.  It is how many CORRECT business rules and decisions you can implement that bring benefit to your organization.

[1]  Business Rule Concepts:  Getting to the Point of Knowledge (Fourth Edition), by Ronald G. Ross (2013).  ISBN 0-941049-14-0, URL:  return to article

[2]  Building Business Solutions:  Business Analysis with Business Rules, by Ronald G. Ross with Gladys S.W. Lam, An IIBA® Sponsored Handbook, Business Rule Solutions, LLC, October 2011, 304 pp.  URL:  return to article

[3]  "Establishing an Enterprise Rule Management Capability," by Veronica O'Grady, presented at Business Rules Forum (2012), Hollywood, FL, USA.  Veronica will be sharing her success in a future article on BRCommunity.  Stay tuned, or contact me for more details.  return to article

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Standard citation for this article:

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Gladys S.W. Lam, "Estimating the Time Required for Business Rules Harvesting — Part 2: Provide the Estimate" Business Rules Journal, Vol. 14, No. 2, (Feb. 2013)

About our Contributor:

Gladys  S.W. Lam
Gladys S.W. Lam Co-Founder & Principal, Business Rule Solutions, LLC , Publisher, Business Rules Journal and Executive Director, Building Business Capability (BBC)

Gladys S.W. Lam is a world-renowned authority on applied business rule techniques. She is Principal and Co-Founder of Business Rule Solutions, LLC (, the most recognized company world-wide for business rules and decision analysis. BRS provides methodology, publications, consulting services, and training. Ms. Lam is Co-Creator of IPSpeak, the BRS methodology including RuleSpeak®, DecisionSpeak and TableSpeak. She is Co-Founder of, a vertical community for professionals and home of Business Rules Journal. She co-authored Building Business Solutions, an IIBA® sponsored handbook on business analysis with business rules.

Ms. Lam is widely known for her lively, pragmatic style. She speaks internationally at conferences, public seminars and other professional events. She is also Executive Director of Building Business Capability (BBC) Conference, which includes the Business Rules & Decisions Forum and the Business Analysis Forum.

Ms. Lam is a world-renowned expert on business project management, having managed numerous projects that focus on the large-scale capture, analysis and management of business rules. She advises senior management of large companies on organizational issues and on business solutions to business problems. She has extensive experience in related areas, including BPM, structured business strategy, and managing and implementing information systems.

Ms. Lam is most recognized for her ability to identify the source of business issues, and for her effectiveness in developing pragmatic approaches to resolve them. She has gained a world-class reputation for fostering positive professional relationships with principals and support staff in projects. Ms. Lam graduated from the University of British Columbia with a B.S. in Computer Science.

Read All Articles by Gladys S.W. Lam

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