Requirements Elicitation Techniques Part 5 – Data Modeling

Planning

Data modeling is a complex topic. Becoming a professional data modeler takes months or years of education plus practical experience. It is not my intent to teach data modeling in this brief post, but to show how it related to requirements elicitation.

I introduced some of the concepts of data modeling in Part 4 of this series, “Business Rules Analysis”. The relationships between entities are the business rules and they are fixed in the structure of the data. Examples of these rules are “A Customer lives at one or more Addresses” and “An Address may contain one or more Customers”.

Entities can be found in the nouns in your requirements. They are people, places and things about which the organization wishes to store data. In the example above, “Customer” and “Address” are entities and are therefore capitalized in the rules statements.

Attributes are the elemental pieces of data that are associated with each Entity. In the logical data model, each attribute must be stored with one and only one Entity. The logical data model represents the business Entities, Attributes and Relationships without regard to physical implementation.

The physical data model represents how the logical data model will be implemented in a relational database. Here are two examples of the differences between the logical and physical data models:

  • In the logical model, you can have “many to many” relationships as in the Customer / Address example above. In the physical model you cannot implement many-to-many relationships, so there would need to be an additional table to store each Customer / Address combination.
  • In the logical model,  Attributes belong to one and only one entity. In the physical model, attributes can be included in multiple entities due to inclusion on table keys or for performance reasons.

The data is an important part of requirements gathering. It is an important tool in Event Discovery, as you will ask data related questions such as “What does having this data allow you to do?” and “If I took this data away, what would it prevent you from doing?” I would recommend all Project Managers at least be able to read and understand an Entity-Relationship diagram.

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Requirements Elicitation Techniques Part 4 – Business Rules Analysis

Planning

According to the IIBA, a business rule is a specific, actionable, testable directive that is under the control of an organization and supports a business policy. Business rules should be documented independently of how they will be enforced.

“Operative Rules” are intended to guide the actions of people. They are typically found in an organization’s Standard Operating Procedures Manual. For example “an order cannot be placed if the billing address provided by the customer does not match the address on file with the credit card provider”. It is always possible that associates will not always follow an Operative Rule. When you are doing a current system analysis, you may very well find documented rules that are handled differently in each location. By finding out the root cause of why a rule isn’t being followed, it could present a good opportunity to change the rule.

“Structural Rules” structure the knowledge of the organization and cannot be violated. For example “an order must have one and only one payment method”. This type of rule is usually enforced systemically. They can be uncovered during data analysis by constructing an Entity-Relationship diagram. The relationships between entities are the Business Structural Rules.

Other examples of Structural Rules:

  • A Product can be purchased by zero, one or many Customers.
  • A Sales Transaction contains one or more Products
  • A Discount can be applied to zero, one or more Products.
  • A Customer may Purchase zero, one or more Products.

The “zero” relationship is of special interest. It is useful for uncovering additional requirements. For example, in the example above “A Customer may purchase zero, one or more Products” you may ask “How can a Customer purchase zero products?”

The answer may be “A Customer might only apply for a Store Credit Card” or “A Customer may only wish to be added to an email list”. These answers would generate follow up questions regarding the scope of the project.

Requirements Elicitation Techniques Part 3 – Benchmarking

Planning

The technique of “Benchmarking” is sometimes used in the Requirements gathering process. You compare your company’s processes and performance metrics to industry best practices from other companies. The knowledge uncovered in these investigations can be used in process improvement initiatives or to solve thorny problems you encounter on your project. I have managed many projects where a typical question in a meeting is “What does Company X do in this case?”. “Company X” is typically the main competition for your company and is usually recognized as an industry leader in the area under study. You may or may not get “Company X” to speak with you on a particular topic, depending on the relationship and the level of competition.

Benchmarking can save a lot of time on a project by avoiding the “let’s reinvent the wheel” syndrome. If someone else has figured it out, why waste your own time? Now you may find their solution cannot be completely adapted to your specific situation but there are usually as least some pieces that can be used and be very valuable.

Benchmarking is a supplementary requirements technique. It will never be the only technique you use but can add important additional information to the requirements process. On every project you should at least ask yourself if Benchmarking can add value to the requirements process.

Requirements Elicitation Techniques Part 2 – Acceptance Criteria

Planning

If you search the Internet for “Acceptance Criteria” you will see definitions like this: “Acceptance Criteria are the conditions that a software product must satisfy to be accepted by a user, customer or external system.” There are no shades of grey, the condition either satisfies the criteria or not. There are no “90% satisfies”.

Acceptance Criteria should be established before development begins. The reason for this is that the criteria needs to guide the development. If you write them during or after the development, you will just be verifying what was built and not the customer intent.

Like all good business requirements, the criteria should be “what” not “how”. For example, you might state “Upon submission of the completed application a notification is sent to the Director”. You don’t want to state “Upon clicking ‘Submit’ an email is sent to the Director”. Avoiding implementation specifics opens up new possibilities for a design solution.

In many ways, the “Event/Response method” (see my prior posts on this topic) and “Acceptance Criteria” are very similar. With Event/Response, we document a triggering event, the data sent and who sends it, what we do with it, the outputs and who receives them. With Acceptance Criteria, many use the format “Given some precondition, when I do some action, I expect some result”. These are essentially the same things although Acceptance Criteria can be at a lower level (the Use Case and Functional Requirements level).

You do not approach your user or customer and ask “What are your acceptance criteria?”. This will mostly elicit blank stares. You will want to use other elicitation methods such as Event/Response and Use Cases, and the derive the Acceptance Criteria from there. You can do this by prioritizing your requirements (e.g. “priority 1 = must have or cannot go live, priority 2 = can go live without it but must have within 1 month of go live, priority 3 = nice to have if it fits within the budget and schedule”). In this case, priority 1 requirements are the acceptance criteria for go live and priority 2 requirements are the acceptance criteria for project completion.

Some examples of Acceptance Criteria:

  • If I am a System Administrator, I can add, update or delete accounts.
  • I can search for users by last name and can enter a partial string and receive the results of all that qualify
  • I can filter my staff by availability for a given shift

Requirements Elicitation Techniques Part 1 – Overview

Planning

In the previous series of posts I introduced my favorite requirements elicitation technique, “Business Event/Response”. Of course there are many other techniques which can act either as complementary to or in place of “Business Event/Response”. The techniques you choose depend on many factors including the knowledge depth of the Subject Matter Experts (SME), the availability of documentation, time constraints, etc.

A skilled Project Manager that is also a seasoned Business Analyst is a very valuable commodity. I encourage all PM’s to increase their BA ability by reading books, attending webinars and seminars, and putting their new knowledge to practice. There is no substitute for actual work experience in this realm.

Here are the topics I will address in the series:

  • Part 1 – Overview
  • Part 2 – Acceptance Criteria
  • Part 3 – Benchmarking
  • Part 4 – Business Rules Analysis
  • Part 5 – Data Modeling
  • Part 6 – Document Analysis
  • Part 7 – Interviews
  • Part 8 – Non-functional Requirements
  • Part 9 – Observation
  • Part 10 – Prototyping
  • Part 11 – Root Cause Analysis
  • Part 12 – Surveys and Questionairres
  • Part 13 – SWOT Analysis
  • Part 14 – Summary