Software Architect's Handbook

Procedural cohesion

A module exhibits procedural cohesion when its elements have been grouped together because they always execute in a particular sequence. For example, payment processing for a customer placing an order might involve the following steps being executed in a particular sequence:

• Gathering payment information
• Validating payment method details
• Checking whether funds are available or whether there is enough available credit

• Persisting the order in a database
• Checking inventory levels
• Creating a back order or canceling an order based on inventory
• Sending the order for fulfillment
• Sending an email confirmation to the customer

Although the various parts are all related by the order of execution, some of the individual activities ...