Environmental Model Specification$($dfd and erd diagram based on the given information below$)$

Context Level DFD:

External Entities: Users, Admin, Payment Gateway, Expert Database

Processes: User Registration, Course$/$Plant Management, Payment Processing, Forum Interaction, Reporting

Data Flows: User Data, Course$/$Plant Information, Payment Data, Forum Posts, Certification Results

Data Flow Diagram $($Level $1)$:

Explanation:

Processes: User Registration, Course Enrollment, Plant Purchase, Payment Processing, Expert Recommendation, Forum Interaction, Reporting

Data Stores: User Database, Course Database, Plant Database, Payment Database, Forum Database, Certification Database

Step $4$

$4\mathrm{.}3\mathrm{.}2$ Internal Model Specification

Entity Relationship Diagram $($ERD$)$:

Entities: User, Course, Plant, Payment, Expert, Forum Post

Relationships: User$-$Course Enrollment, User$-$Plant Purchase, Forum Post$-$User Interaction

Data Dictionary:

Definitions for major data flows and data stores.

Process Specifications $($Pspecs$)$:

Detailed specifications for elementary processes like User Registration, Payment Processing, Forum Interaction.