Example for Transaction Mapping

Let’s illustrate an example of transaction mapping using a simple online shopping system as described in the context of designing data flow diagrams (DFDs) for software engineering.

Step 1: Create a Level 0 DFD.

At the highest level, the Level 0 DFD illustrates key actions of the online shopping system:

1. Customer Management
2. Product Management
3. Order Management
4. Payment Processing
5. Shipping

These processes represent the major functionalities of the system.

Step 2: Create Lower-Level DFDs.

For each of the processes identified in the Level 0 DFD, create lower-level DFDs to explain the involved processes in detail. For example:

Order Management Process

• Sub-process: Place Order, Update Order, Cancel Order
• Data Stores: Order Database
• Data Flows: Order Information (from Place Order to Order Database), Updated Order Status (from Update Order to Order Databases

Step 3: Add Data Stores.

Include data stores in the DFD to represent where data is stored within the system. For Example:

• Customer Database: Stores customer information like name, address, and contact details.
• Product Database: Stores product details such as name, description, price, and availability.
• Order Database: Stores information related to customer orders, including order ID, items purchased, quantity, total price, and shipping details.

Step 4: Add Data Flows.

Show data flows between processes using arrows to indicate the movement of data within the system. For example:

• Data Flow: ‘Order Information’ flows from the ‘Place Order’ process to the Order Database, capturing details of the customer’s order.
• Data Flow: ‘Updated Order Status’ flows from the ‘Update Order’ process to the Order Database, reflecting changes in the order status.

Transaction Mapping

In transaction mapping, each data item or transaction (e.g., placing an order, or updating order status) triggers information flows and functions within the system. For instance:

1. Placing an Order Transaction

• Triggers data flow of ‘Order Information’ from the ‘Place Order‘ Sub-process to the Order Database.
• Initiates processes related to inventory management and order fulfillment.

2. Updating Order Status Transaction

• Triggers data flow of ‘Updated Order Status’ from the ‘Update Order’ Sub-process to the Order Database.
• May initiate processes related to notifying customers, updating inventory, or generating shipping labels.

Transaction mapping has turned out to be a decisive aspect in the Software Engineering arena. It guarantees that the business processes are properly matched, the design does not use too many resources, the data is accurate, the communication between the departments is effective, and there’s room for scaling the business up and testing/validation processes that maintain quality. Here we assume we talk about a development process consisting of a structured chain of steps and let’s imagine that an example of such a process is shopping from the online store. This way, the blocks would be more accurate in transactions, becoming more stable and complete.