Skip to content
Contact us
  • There are no suggestions because the search field is empty.

Crew Logic vs. Hard Logic

In CPM scheduling, some relationships are driven by how the building must physically go together, also known as hard logic. Others are driven by how you choose to staff the work, also known as crew logic.

Understanding the difference between hard logic and crew logic is critical to building a schedule that is both realistic and defensible.

Hard logic:

Hard logic represents relationships that are physically required. One activity must happen before another because the work itself demands it.

If you removed the predecessor, the successor simply couldn’t happen.

Examples:

  • Concrete must cure before steel erection begins.
  • Structural framing must be complete before drywall installation.
  • Roofing must be in place before interior finishes are protected from weather.

These relationships are non-negotiable. They are driven by physics, materials, and sequencing requirements. Hard logic:

  • Defines the true build sequence
  • Determines the real Critical Path
  • Makes your schedule technically sound
  • Strengthens defensibility in delay analysis

If you’re ever asked, “Why does this activity have to follow that one?”  and the answer is “Because the building won’t stand otherwise”, that’s hard logic.

Crew Logic

Crew logic represents relationships driven by resource decisions, not physical necessity.

The work could potentially occur at the same time, but you choose not to because of manpower, equipment, or staffing limitations.

Examples:

  • One drywall crew works floor by floor instead of all floors simultaneously.
  • The same electrical crew services multiple areas sequentially.
  • A shared lift or crane forces work to be staggered.

Crew logic:

  • Reflects how you plan to execute the work
  • Helps model realistic manpower flow
  • Can change over time
  • Should be documented clearly

Unlike hard logic, crew logic can often be adjusted by:

  • Adding crews
  • Increasing shifts
  • Renting additional equipment

By clearly identifying hard logic and crew logic in your CPM schedule, you create a plan that reflects both the realities of construction and the strategy behind how you execute it.