Question

Characterize the following design purpose as creational, structural, or behavioral. Explain your conclusion clearly. We must build an application that allows users to build and change their stock portfolio with a various kinds of mutual fund picks from specified subcategories. The mutual fund categories are technology, old industries, utilities, real estate, and mining. The application allows users to pick categories. It then makes portfolio recommendations depending on the user's choice. For example, the user can ask for a low-risk portfolio of utilities and mining stocks, and the application describes its recommendations within these constraints.

Short answer

The design purpose is behavioral, as it involves dynamic responses to user input.

Step-by-step solution

Identify Key Aspects of the Problem

The problem involves creating an application that helps users construct and modify their stock portfolios based on selected categories of mutual funds. These categories include technology, old industries, utilities, real estate, and mining. Users can specify preferences, such as low-risk investments, and the application provides recommendations.

Determine the Nature of the Design Requirement

Consider the requirement: the application needs to provide recommendations based on user input. This points to the need for dynamic behavior in response to user choices. It indicates that the focus is on how the objects interact to deliver the desired outcome (recommendations), not merely on the creation or structure of the components themselves.

Categorize the Design Purpose

Given that the application adjusts recommendations based on user inputs and specific constraints, it's clear that the problem is centered around the behavior of the system: how it responds and delivers different portfolio suggestions. This aligns with a behavioral design pattern, which focuses on the interactions and responsibilities among different components to produce the desired behavior.

Conclusion

The design purpose is behavioral because it aims to dynamically adjust portfolio recommendations based on user preferences and specified constraints. It focuses on how different components interact and the logic governing these interactions to achieve the expected outcome.

Key concepts

Behavioral Patterns

In software design, patterns describe solutions to common design problems. Behavioral patterns specifically focus on the ways that objects communicate and interact in a system. They define how tasks are handled through the cooperation of objects, focusing on the dynamics of invoking behaviors, rather than statically predetermined operations.

The primary goal of behavioral patterns is to make the communication between objects clear and manageable. They allow objects to change state or behavior based on interactions with other objects, encouraging flexibility and reusability. These patterns include strategies such as Observer, Strategy, and Command, among others.

• **Observer Pattern:** Useful for notifying multiple objects about state changes.
• **Strategy Pattern:** Allows defining a family of algorithms and making them interchangeable.
• **Command Pattern:** Encapsulates requests as objects, thereby allowing queueing and logging operations.

By implementing behavioral patterns, developers ensure that the software can adapt to uncertainty and change over time. The dynamic nature of these patterns supports actions like responding to user inputs and adjusting to new scenarios quickly.

Portfolio Management Application

A portfolio management application is a digital tool used by investors to create and manage their investment collections. It allows users to monitor, buy, and sell assets like stocks, bonds, and mutual funds.

These applications offer various features to enhance the decision-making process:

• **Asset Categorization:** Users can organize investments into different categories such as technology, utilities, or real estate, making it easier to manage them.
• **Performance Tracking:** The application provides insights into how each asset or portfolio performs over time, assisting in assessing profitability and risk.
• **Automated Transactions:** Users can automate buying or selling based on certain conditions to optimize their investment strategies.

The key advantage of portfolio management applications is the ability to make informed decisions rapidly. By having access to real-time data and dynamic charts, users can fine-tune their portfolios to meet specific investment goals and risk appetites efficiently. An essential feature these applications have is to recommend actions based on personal criteria set by the user, which directly ties into the use of behavioral patterns to offer dynamic interactions.

Dynamic Recommendations

Dynamic recommendations involve providing tailored advice to users based on their specific inputs, preferences, and interactions with a system. In the context of a portfolio management application, this means suggesting investment strategies tailored to user-defined parameters.

These recommendations are made possible by harnessing various types of data and algorithms that can adapt to user behavior and market changes in real-time. Some key aspects include:

• **User Profile Analysis:** Understanding user preferences, risk tolerance, and financial goals to offer relevant advice.
• **Market Trends:** Keeping up with current market data to offer timely and advantageous recommendations.
• **Scenario Simulation:** Running different investment scenarios to predict outcomes and guide user decision-making.

Ultimately, dynamic recommendations enhance user experience by offering personalized suggestions that simplify complex decision-making processes. They rely on the sophisticated interaction of different system components to provide insights that are both relevant and actionable.