Temporal/Deadline Orderings

Input: $ARGUMENTS

Overview

When external deadlines dominate, order work by temporal constraints. What must happen by when, what converges when, and what can slip.

Ordering Rules

Rule 1: Earliest Deadline First (EDF)

• Process the item with the nearest deadline first
• Optimal for single-resource scheduling to meet all deadlines
• When: multiple items with different due dates

Rule 2: Backward Schedule from Deadline

• Start from the deadline, work backward to find latest possible start dates
• Each task: latest finish = deadline (or successor’s latest start)
• Latest start = latest finish - duration
• When: project scheduling, meeting fixed dates

Rule 3: Time-Critical Path

• Focus on the sequence that determines total duration
• Accelerate this path; other paths have slack
• When: multi-path projects with a hard end date

Rule 4: Convergence Point Scheduling

• When multiple streams must merge at a point (launch, event, integration)
• Schedule backward from convergence point
• Streams that take longest start first
• When: events, releases, coordinated deliveries

Rule 5: Buffer Placement

• Don’t pad individual tasks (Parkinson’s law — work expands)
• Place time buffers at convergence points and project end
• Monitor buffer consumption for early warning
• When: uncertainty about task durations

Application

1. Identify all deadlines and convergence points
2. Map dependencies
3. Schedule backward from deadlines
4. Identify critical path and focus resources there
5. Place buffers at merge points

When to Use

• Deadline-driven projects, event planning
• Coordinated releases, any time-constrained work

Verification

• All deadlines identified
• Backward schedule complete
• Critical path identified
• Buffers placed at merge points