Requirements Analysis Using Event / Response and Use Cases: Final Summary

Planning

In the preceding posts, I gave you some guidance on how to execute the Event/Response methodology for scope and requirements analysis. In this last of the series of posts on this topic, I will take the 5,000 foot view and put it all together in a summary of steps.

  • Step 1 – Define the Business Objectives (the measurable benefits realized after implementation). These will be used to verify the scope and requirements.
  • Step 2 – Define the Project Objectives (the products, services and/or results delivered at project implementation). These will also be used to verify scope and requirements.
  • Step 3 – The Context Diagram. Look at the area under study as an outsourced business, with Suppliers (of data) and Customers (recipients of data/information/results).
  • Step 4 – The Event List. This represents your “business model”. You define all of the events that “wake up” your business and require a planned response. In the prior posts, I presented a variety of techniques for fleshing out these events. Included in the Event List are your business processes and stakeholders.
  • Step 5 – Validate the Event Model. Compare your event scope with the Business and Project Objectives and verify with the Project Sponsor that all objectives are covered by this scope.
  • Step 6 – Construct Use Cases. Use the defined business processes in the Event Model as the starting point for creating Use Cases.
  • Step 7 – Test Planning and Execution. The Event Model is a wonderful framework in which to define your test scenarios and cases. Take advantage of all the work you did in the requirements phase to make your test planning and execution easier.

That’s it for this topic. I hope you found it informative and useful. I have used this technique successfully in many real-world projects.

Requirements Analysis Using Event/Response and Use Cases: Test Planning & Execution

Planning

In addition to being a great way to elicit the complete scope of a project, the Event/Response methodology delivers a comprehensive framework for test planning and execution. When using this methodology, what many call “User Acceptance Testing” can be replaced by the term “Event Testing”.

In my prior posts on this topic, I identified the primary deliverables of the Event/Response methodology as:

  1. The Event List (containing the event that triggers the response, the origin and data content of the information flow into your “business”, the named processes, the outputs of the processes and the destinations of the outputs), and
  2. The Use Cases. You can plan to test by simulating the actual Events, creating the data flows, executing the processes and examining the outputs. The Use Cases give you a good start on creating the data and usage variations for each Event. Doing this yields a direct mapping of the scope and requirements to the test cases and execution.

Note that since the Event List also contains the roles of the actors initiating the events and processes, as well as the roles receiving the outputs, security testing can also be built into this framework.

Another major plus of planning and executing the tests this way is that you are testing the system as it will actually be used in context, as opposed to functional testing which tests bits of functionality in isolation.

A recent project of mine used this methodology and yielded 180 Events and over 1,600 test cases. Because of this comprehensive approach, the system was very well tested and only experienced minor problems after implementation.

Requirements Analysis Using Event / Response and Use Cases: Functional Requirements

Planning

In my previous post on the topic of Requirements Analysis, I showed you how to derive your Use Cases from the Event List. I also presented a list of recommended elements to be included in each Use Case. The primary element is the list of steps taken by the Actors and the System they interact with. Within these steps are the Functional Requirements.

In my initial post in this series, I mentioned that starting and ending requirements gathering with functional requirements was not very effective. Why? Because functional requirements are at too low of a level and places the burden on the memories of SME’s (Subject Matter Experts) instead of the analytical questions of the Business Analyst, where the burden really belongs. For large systems, if you start and end with functional requirements you will almost assuredly have an incomplete set of requirements.

Using the Event/Response methodology, we started with Event Discovery, using a wide variety of techniques to generate the questions the Business Analyst needs to ask. We fleshed out the Events, which led to discovery of the business processes in scope. We validated the model to make sure we had the complete list of Events and processes. We used the processes to create our Use Cases. We will now examine the Use Cases to derive the functional requirements. This is an organized, top down approach to requirements that will output as complete a set of requirements as is possible.

Within the steps of the Use Cases are things like “Insert Debit Card”, “Read Card”, “Select Action”, “Browse by Last Name”, etc. These are all functional requirements that must be satisfied by the solution. The system design must address all of these requirements. However, these are low-level capabilities and are not a good source for overall system design. By using the Event Model, the system designer can see the big picture and design a friendlier, more efficient system than is possible using just the functional requirements.

In the next post I will address the advantages of the Event Model when designing and executing tests.

Requirements Analysis Using Event/Response and Use Cases: Building Use Cases

Planning

Now that you have a complete and comprehensive Event List, you can now use this to create your Use Cases. Before I show you how, let’s first define “Use Case”:

  • A Use Case is simply a list of steps to achieve a goal
  • It may have multiple paths (for example, the Use Case for getting cash from an ATM has the normal path, plus an alternate path for the case where a user asks for more money than in their account)
  • A Use Case Scenario is a specific path thru the Use Case

Column 4 of the Event List (“…Then We Do This”) contains the names of all of the business processes within the scope of your project. Take each of these process names and create the corresponding Use Cases. Here is a collection of data elements which you can include in the Use Cases:

  • Use Case Name and ID (you can use a scheme such as capital U + the Event Process ID + decimal point + the Use Case sequential number. For example, U2.1.1)
  • Use Case brief description (The process name and perhaps an additional clarifying sentence or two)
  • Sub-System Name (e.g. “Accounts Payable”)
  • Triggering Event (from the Event List)
  • “Actors” (Stakeholders that interact with or are affected by the Use Case; Your Event List is a great starting point for identifying your Stakeholders)
  • Pre-conditions: What needs to be true before the execution of this Use Case (for example, “Customer ID has been established”)
  • Post-conditions: The state of the system after execution of the Use Case (for example, “Employee has possession of a company credit card”)
  • Process Flow. Include a column for the Actors and a column for the steps executed by the Actors and the System. Do this until the process is complete and accomplishes the Post-conditions.

In the next post I will discuss deriving Functional Requirements from the Use Cases.

Requirements Analysis Using Event/Response and Use Cases: Validating the Model

Planning

In the prior posts on “Event Discovery”, you completed your initial Event Model. I say “initial” because in the process of validating the model, you may discover additional events.

In order to validate the model, you first compare it to your Project Objectives (the implementation deliverables that survive and are maintained after the project is considered complete). For each Project Objective you need to ensure that you have one or more Events and Business Processes that will contribute to reaching that objective. If you don’t find at least one, you are missing at least one event and must cycle back to event discovery to find it or them.

When you are finished validating against the Project Objectives, you will then validate against the Business Objectives. As a reminder, Business Objectives…

  • Contribute to the business strategy
  • Make or save money
  • Take advantage of opporunity
  • Provide competitive advantage
  • Respond to new laws and regulations
  • Are measurable

Compare the Event Model against the defined Business Objectives and ask the Core Team and the Project Sponsor if this scope will directly or indirectly address the objectives. If one or more objectives are not addressed, then you will continue with event discovery until you are satisfied the Business Objectives are satisfied by the model.

In the next post I will present how Use Cases are derived from the Event Model.

Requirements Analysis Using Event/Response and Use Cases: Event Discovery Part 7

Planning

The posts in this series so far have covered identifying External Events, which in most cases will constitute the majority of your Events. There are two other types of Events you also need to identify:

  • Time-based Events
  • System State Events

To identify Time-based Events you can simply ask your SME’s (Subject Matter Experts) if there are any processes that run based on time (e.g. “every X hours/days/weeks/months”, “First Monday of every month”, “Every other Friday”, etc). Some Events that run based on time are only done so due to technical limitations, either real or perceived. You do not want to classify these Events as time-based. For example, if they say “We run an interface from our HR system to our Time-Keeping system every two hours”, that is a choice, not a requirement. In an ideal world, those two systems would always be instantaneously in sync. Do not let technical limitations limit your requirements.

An example of a good time-based requirement is “We submit monthly tax reports to state and local governments”. The timing is a requirement of External Entities and must be honored.

System-State Events can be identified when you are reviewing the relevant data elements. You can ask if any change in the value of an element automatically triggers a process. For example, in an inventory system a System-State Event might be “When the on-hand quantity reaches 5, a reorder is triggered”. In an HR system, a promotion would trigger events related to pay, benefits, organization, etc.

Once you have added the Time-based Events and the System-State Events to the External Events in your Event Model, it is time to validate the model. That will be the subject of Part 8 in this series.

Requirements Analysis Using Event Response / Use Cases: Event Discovery Part 5

Planning

This is Part 5 in my series of posts on Event Discovery. The technique I present in this post is very effective in cases where you know little or nothing about the business area under study.

Using the methods presented in my prior posts, you are able to discover Entities (e.g. “Customer”, “Sale”, “Store”, etc.) for which you need to store persistent data. As you flesh out the data needs for each Entity, here are some powerful questions that enable you to discover more events:

  • For new data elements (i.e. data that is not currently being captured in the existing system), ask “Why do you need this data? What will it enable you to do?”. The answers will be business processes that can be entered on the Event List. Once you have at least one cell of information for a row on the Event List, you can fill in the rest of the row with the relevant questions. For example, if the new piece of data is “Customer Mobile Phone #”, your business partners may say “We want to conduct text message marketing campaigns”. That answer leads you to the questions on the Event List such as “What Event starts a campaign”, “What is the input data and who/what provides it”, “What are the business processes”, “What are the outputs and who/what receives them”.
  • For existing data elements (i.e. data that is currently captured by the existing system) ask “If I took this data away from you, what will it prevent you from doing?”. This is a question that will get your business partners to think deeply about the answer, as the thought of losing something usually heightens awareness. For example, if the data element in question is the Employee Address, this may prompt your business partners to reveal all of the direct mail items sent to an Employee (an example would be “Start or open enrollment for benefits), and these would have corresponding events that initiate them.

The Event Discovery series continues in the next post.