Case Study: Elaborating the “Browse Products” Use Case in an E-Commerce Platform

Introduction

In today’s highly competitive e-commerce landscape, the ability for customers to efficiently discover and evaluate products is a foundational element of user satisfaction, conversion rates, and long-term platform loyalty. The “Browse Products” use case represents one of the most frequently executed journeys in any online retail system — serving as the primary gateway through which users explore the catalog before progressing to core business goals such as adding items to the cart or completing a purchase.

This case study demonstrates a structured requirements elaboration process starting from a high-level UML use case diagram, through a detailed textual use case specification (including actors, main success scenario, alternative and exception flows, pre- and postconditions), and culminating in a precise activity diagram that visualizes the dynamic decision points, user actions, and system responses. By applying this progressive refinement approach — supported by tools such as Visual Paradigm and PlantUML notation — we create clear, unambiguous, and implementable artifacts that bridge the gap between business stakeholders, UX designers, developers, and quality assurance teams.

The example focuses on a realistic modern e-commerce browsing experience, incorporating common features such as category navigation, keyword search, filtering, sorting, and product detail navigation, while explicitly handling edge cases like zero-result scenarios and graceful degradation. This elaboration not only supports accurate development and testing but also provides a reusable template for modeling similar discovery-oriented use cases across digital product platforms.

1. Context & Use Case Identification

System: Modern E-Commerce Platform (web & mobile) Use Case Name: Browse Products Use Case ID: UC-001 Actors:

• Primary: Customer (registered or guest)
• Secondary: System (Product Catalog Service)

Brief Description The customer explores the available product catalog to discover items of interest. This includes viewing categories, searching, filtering, sorting, and drilling down into product details — forming the entry point for most shopping journeys.

Priority: High (core user-facing capability) Frequency: Very high (most sessions begin here) Scope: User goal / business

2. Detailed Use Case Description

Use Case Name: Browse Products Primary Actor: Customer Secondary Actor: E-Commerce System (Catalog Service)

Description Allows customers to discover and evaluate products by navigating categories, performing keyword searches, applying filters (price, brand, rating, etc.), sorting results, and viewing detailed product pages. This use case does not include adding to cart or purchasing — those are separate (included or extended) use cases.

Preconditions

• The e-commerce platform is online and accessible
• The product catalog database is populated and up-to-date
• Customer has opened the website/app (logged in or as guest)

Postconditions

• Customer has viewed one or more product listings / detail pages
• System has recorded browsing events for analytics, recommendation engine & personalization
• Customer may proceed to Add to Cart, Place Order, or exit

Main Success Scenario (Happy Path)

1. Customer navigates to the products/browse page (home, category landing, or search landing)
2. System displays top-level categories and a prominent search bar
3. Customer chooses one of the following actions (any order, repeatable):
   • Selects a category → system shows products belonging to that category
   • Enters a search keyword/phrase → system performs search
4. If search is performed and results exist → system displays matching products (with pagination)
5. If no results → system shows “No products found” message + suggested alternatives
6. Customer optionally applies one or more filters (price range, brand, rating, color, size, etc.)
7. System updates the product list according to active filters
8. Customer optionally changes sort order (relevance, price low→high, price high→low, newest, popularity, rating)
9. System re-sorts the displayed list
10. Customer clicks/taps a product card → system opens the Product Detail Page
11. Customer continues browsing (returns to list) or ends session

Alternative Flows

• 3a. Customer does nothing (just landed) → system shows featured/all products or personalized recommendations
• 6a. Filters produce zero results → system shows warning + option to clear filters
• 10a. Product is out of stock → detail page shows “Out of stock” + possibly “Notify me” option

Exception Flows

• 4a. Search service timeout / failure → system shows error message + fallback to category browsing
• Internet lost during browsing → client-side cache shows previously loaded items (progressive enhancement)

Special Requirements

• Responsive design (mobile + desktop)
• Lazy loading / infinite scroll support
• SEO-friendly URLs for categories & search results
• Accessibility (WCAG 2.1 AA): keyboard navigation, screen reader support for filters

3. Activity Diagram (PlantUML – ready to paste into Visual Paradigm Chatbot)

This activity diagram captures the main & alternative paths described above

@startuml

skinparam {
ArrowColor #424242
ArrowFontColor #424242
DefaultFontSize 14

Swimlane {
BorderColor #9FA8DA
BackgroundColor #E8EAF6
FontColor #303F9F
}

Activity {
BorderColor #FF8F00
BackgroundColor #FFECB3
FontColor #3E2723
}
}

start
:Open Browse Products Page;
:Display Categories & Search Bar;
if (Customer selects category?) then (yes)
:Show Products in Category;
else (no)
:Show All Products;
endif
if (Customer enters search term?) then (yes)
:Search Products;
if (Products Found?) then (yes)
:Display Search Results;
else (no)
:Show “No products found” message;
endif
else (no)
:No Search;
endif
if (Customer applies filters?) then (yes)
:Apply Filters;
:Update Product List;
endif
if (Customer sorts results?) then (yes)
:Sort Products;
endif
if (Customer selects product?) then (yes)
:Open Product Detail Page;
else (no)
:Continue Browsing;
endif
:End Browsing Session;
stop

@enduml

Summary – Progression of Elaboration

1. Use Case Diagram → high-level actors & goals (Browse Products, Add to Cart, Place Order, etc.)
2. Use Case Description → structured narrative with flows, pre/postconditions, exceptions
3. Activity Diagram → visualizes the dynamic behavior, decisions, loops, and user-system interactions

You can copy the PlantUML code above directly into Visual Paradigm Chatbot (or any PlantUML-compatible tool) to generate the diagram. Let me know if you’d like to extend this case study with:

• a Sequence Diagram (customer ↔ browser ↔ backend),
• a UI wireframe sketch description, or
• the next use case (Add to Cart or View Product Details).

Happy modeling!

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