Requirements Analysis Using Event Response and Use Cases: Event Discovery Part 2

Planning

In the previous post I discussed how to use the Context Diagram for initial Event discovery. In this post I will present how to use the outputs from your Event List to discover more events.

The fifth column in your Event List (the one labeled “Which creates this…”) are the outputs of your business processes. You can use these outputs to discover more Events by asking the following questions for each output:

  • Does the output go to a “Customer”? (an entity outside of the center bubble in the Context Diagram). If yes, then that is where the output ends. If no, then that means it must be input to another event or the output has no purpose. Ask your SME’s (Subject Matter Experts) what other business processes use this data. For each identified business process, you can flesh out the Event List row for that process.
  • What are the “Create” Events for this output? These are the Events that result in the establishment of a new row (or rows) of data in the output in question. For example, the sale of a product creates a Sales Transaction record. Note there may be more than one Event that creates rows in this output.
  • What are the “Change” Events for this output? For this you may need to examine each data element in the output. For each element, ask the SME’s what business processes change this data. Use these answers to continue to build the Event List.
  • What are the “Delete” Events for this output? These are the Events that result in the logical or physical removal of a row in the output. For example, if the record retention requirement for the output is 5 years, then the time-based event “Record Retention Limit Reached” will be added to your Event List.

Now that you have added many more rows to your Event List, you will have more outputs to examine. Cycle back thru the Event List outputs and ask the same questions listed above. You will find your Event List grows very quickly!

In the next post I will continue to present additional techniques for Event Discovery.

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Requirements Analysis Using Event/Response and Use Cases: Event Discovery Part 1

Planning

In prior posts I introduced the Context Diagram and the Event List. In this and the upcoming series of posts, I will define some techniques you can use to discover events and complete the Event List and Context Diagram.

The very first place to start defining events is the Context Diagram. Every input arrow on the diagram represents an event to which your “business” must respond. Remember, our definition of your “business” is the boundary of the business area under study. Inside of the business bubble on the Context Diagram, you have control over the business processes and data flows. Outside the boundary, you can negotiate the interfaces with the Suppliers and Customers but have little or no control over their business processes.

Let’s examine an example of how the Context Diagram can provide events. For this example, let us say the Supplier is an Employee and the input arrow is “Travel Expense Details”.

Our first column on the Event List is “When this happens”. In this example, you would state “Travel Expense Report Submitted”.

The second and third columns are “This Source” and “Gives us This”. In this example, the Source is “Employee”, and “Gives us This” is “Travel Expense Details”.

The fourth column is “Then we do this”. These are the labels of the business processes your “business” will execute upon receipt of the “Travel Expense Details”. You might have a list of processes that looks like this:

  • Verify expenses comply with business policy
  • Approve/Reject Expenses

The fifth column is “Which creates this”. These are the outputs of each business process. The outputs of the first process listed above might be “Valid Expenses” and “Invalid Expenses”. The outputs of the second process listed above might be “Approved Expenses” and “Rejected Expenses”.

The sixth column is “… and we give it to …”. These are the recipients of the outputs listed in the fifth column. In this case the recipient of the Valid and Invalid Expenses could be “Employee’s Manager”. The recipient of “Rejected Expenses” would be the Employee while the recipient of “Approved Expenses” could be the Travel Expense Data Repository.

Be sure to keep implementation details out of this analysis. You don’t want solutions to be constrained by using specifics such as “email:, “reports”, “database”, etc.

In the next post, I will continue the discussion of Event Discovery and show how, once you have a few events listed, you can use these events to discover more events and get the complete scope of the project.

Requirements Analysis Using Event/Response and Use Cases: Elements of the Event List

Planning

I recommend setting up the Event List using Excel. Remember, when I refer to your “business” it means the scope of the area under study. Here are the columns you will need along with their descriptions:

  • Event ID – use a numbering system for your Events so they will be easy to track thru design and testing. I use a scheme where the main number puts the event in context and a number after the decimal point is just a sequential number within that context. For example, Event ID 3.1 where “3” represents sales events and “.1” is the first event in that context.
  • “When This Happens” – this is a brief description of the event that causes your “business” to react with a planned response. For example, “Customer initiates check out”.
  • “This Source” – one or two nouns describing the entity responsible for directly providing data/information to your “business”. Examples are “Associate” or “Customer”. This will match your “Suppliers” on the Context Diagram.
  • “Gives us This” – a brief description of the data/information being provided. Examples are “Time off request” or “Product ID”. This will match the input arrows on your Context Diagram.
  • “Then we do this” – the name of the business process(es) you will execute to respond to this event. For example “Time off request approved/denied” or “Record Sale”.
  • “Which Creates This” – the permanent output(s) of the business process(es). For example “Time off approval” or “Product Inventory Update”. This will match your output arrows on the Context Diagram.
  • “And is Given to…” – The recipients of the output(s). These could be systems, departments, roles, or vendors. This will match the “Customers” on your Context Diagram.

Remember to keep the event items free of technical and implementation jargon. Note my example “Customer Initiates Check Out”. This could be in a store, online or some other means. The “How” will be decided later, in design, and not here.

In the subsequent posts I will show how to do Event Discovery to elicit a complete set of requirements.

Requirements Analysis Using Event/Response and Use Cases: Business Events

Planning

For the purpose of this analysis approach, “Business Events” are anything that occurs that causes your “business” to initiate a business process. Defining all of the Business Events in scope will lead to discovery of the business process in scope.

There are three main types of Business Events:

  1. External: These come from outside of your business and you have little or no control as to when or how often these events occur. Examples are “Customer purchases Product” or “Associate requests time off”.
  2. Temporal: These events happen at regular predetermined intervals. These intervals are required, they are not a business or design decision. Don’t let technology limitations determine the interval. Good Example: “It is time to file quarterly taxes”. Bad Example: “Every two hours the HR system sends employee information to the Financial System”.
  3. Data/System State: Occur when the data or system reaches a predetermined condition. These are usually Business Rules or Policy decisions. Example: “Product is re-ordered when the inventory level reaches 5”.

The input arrows on the Context Diagram are the starting point for event discovery. In the next post I will define the elements of the “Event List”.

Requirements Analysis Using Event-Response / Use Cases: The Context Diagram

Planning

The Context Diagram is the place to start when doing your analysis. It should be done in conjunction with the stakeholders that are most knowledgeable about the business processes for the domain under study. The initial list of Business Events will be derived from the Context Diagram.

Start with a circle in the middle of the diagram. This represents the area of the business in the scope of the project. All of the processes within this circle are in scope and are able to be modified or added to as part of the project scope. Think of it as if this business function were outsourced to a service provider and the Executive Sponsor of the project is the CEO of this service provider. What would they need to know to create a business model?

First, you would want to define “who are my Customers?”. Your Customers are recipients of your business’s outputs (in most projects, these are flows of information and data). Ask the key stakeholders “who are the current recipients of information your business function?”. Draw the Customers as rectangles on the right hand side of the diagram. It is not important at this time that you have the complete list of Customers, only that you have some. We will complete the list of Customers in an iterative process in conjunction with the Event/Response Model.

Next, define the types of information that flow to each Customer. Draw these as arrows from the center circle and connecting to the Customer rectangle. Have a short, high level description of the flow on each arrow.

After that you need to define “who are your Suppliers?”. The Suppliers are providers of the business’s information and data. Ask the key stakeholders “who are the current providers of information for your business function?”. Draw the Suppliers as rectangles on the left hand side of the diagram. It is not important at this time that you have the complete list of Suppliers, only that you have some. We will complete the list of Suppliers in an iterative process in conjunction with the Event/Response Model.

Next, define the types of information that flows from each Supplier. Draw these as arrows from the Supplier rectangles and connecting to the center circle. Have a short, high level description of the flow on each arrow.

Rules for Suppliers and Customers:

  • They can be individuals, roles, departments, organizations, systems, vendors, etc. Anything that is a net originator or receiver of data or information from your “business”.
  • Some entities can be both Suppliers and Customers. so they will have arrows going in both directions.
  • If you are struggling with whether a Supplier or Customer is inside or outside the circle, the general rule is for entities outside the circle, the project has no control over their processes. The project can only change the nature and content of the information flows to and from these entities.
  • There are no flows represented that go from entity to entity. They may exist but they are of no concern to the project.

Here is an example of a Context Diagram:

Context_Diagram

Requirements Analysis Using Event Response / Use Cases: The Event Model

Planning

The Event Model looks at the scope of your project as if this business function is being outsourced to a third party business and your Executive Sponsor is the CEO of that business. This is the new way of thinking about requirements that I referred to in the Overview post.

The Event Model consists of the following elements:

  • The Context Diagram – shows your business boundary as a circle in the center of the diagram with your suppliers, customers and information flows surrounding the center circle. I will present this in detail in the next post.
  • The Event/Response Model – this contains the detail of the events that “wake up your business” and requires the business to have a planned response. It is progressively elaborated in conjunction with the Context Diagram. More on this in a future post.
  • Use Cases – are derived from the Event/Response Model and show the specific steps required for each business response. At the end of the requirements analysis, this becomes (or is the basis for) your “Business Standard Operating Procedures Manual”. Functional Requirements are derived from the Use Cases.

An important thing to remember when creating the Event Model is to keep it independent of technology. It needs to address “what we do” and not “how we do it”. Doing this will help you envision more design alternatives than you would if you locked in a solution at the requirements level.

In the next post I will give you a closer look at how to create a Context Diagram and utilize it to get the requirements discovery rolling.

Requirements Analysis Using Event Response / Use Cases: Business/Project Objectives

Planning

If you search this site using the keyword “objectives”, you will see my prior posts on the importance of documenting your Business and Project Objectives, as well as how to properly define them. Those posts framed objectives in the context of the Project Management process. Having the objectives defined is also critical in the requirements analysis process.

Here are some of the key reasons for knowing your Business and Project objectives in advance of your requirements analysis:

  1. Ensure that everyone on the project team understands the project vision. There is a saying in the military that “no plan survives contact with the enemy”. That is also true for projects (where the “enemy” is usually time and resources). However, if everyone understands the commander’s intent (the “objectives”), then it is easier to change and adapt the plan. Conditions may make you unable to execute the original plan, but you are always responsible for achieving the commander’s intent.
  2. The Objectives guide everyone’s decision making. There are many decisions made each day on a project. They are made by everyone on the team, not just the management. Along with empowering people to make decisions, you must give them the tools to make the right decisions. Chief among those tools is making sure they know and understand the Business and Project Objectives.
  3. The Objectives are used to validate the Requirements Model. At the end of the first round of analysis, you will compare the results to the documented Project and Business Objectives. Do your requirements address all the deliverables in the Project Objectives? If not, another round of analysis is needed. Will the requirements achieve the Business Objectives? If not, understand why. Has your analysis revealed additional Project Objectives? If so, these must be addressed in your Change Management process in order to change your Project Charter.

In the next post I will define the Event Model, with subsequent posts addressing each element in detail.