Creating a Level Zero Data Flow Diagram

Introduction to Level Zero Diagrams

• The speaker introduces the concept of a level zero diagram, which is similar to a context diagram but includes more detailed processes.

• The process symbol in the level zero diagram is "exploded" or decomposed into multiple processes.

Processes in the Hiring System

Creating Job Opening

• The first process identified is "create job opening," labeled as 1.0.

• A data store called "job database" is added to represent where job descriptions are stored, emphasizing that data stores are not included in context diagrams but are in level zero and below.

Receiving Applications

• The second process, labeled 2.0, is "receive application."

• An application database is introduced alongside this process, with data flows being renamed for clarity as they pass through different processes.

Scheduling Interviews

• The third process involves scheduling interviews (process 3), highlighting its importance within large organizations where many managers and applicants interact.

• The speaker explains that scheduling requires input from both applicants and managers regarding their availability.

Data Flows and Schedules

• Information from received applications may include applicant availability, which will be used during the scheduling process.