Introduction
Prime Productivity Time (PPT) is the period during which actual value is added to raw materials through conversion processes such as cutting, bending, welding, milling, drilling, and turning etc. It represents the effective manufacturing time in which transformation occurs.
Key Theoretical Alignment
Lean Manufacturing emphasizes eliminating waste (Muda) to maximize value-adding activities. PPT directly corresponds to this principle by focusing only on the time spent in actual production.
Overall Equipment Effectiveness (OEE) breaks down productivity into Availability, Performance, and Quality. PPT aligns with the Availability factor, ensuring machines and workforce are engaged in value-adding activities with minimal idle time.
Theory of Constraints (TOC) identifies bottlenecks and ensures continuous production flow. PPT follows this by ensuring that material, machines, and labor are optimally synchronized.
To achieve maximum PPT, the production floor should aim to match PPT with total available work hours, excluding only fatigue allowances. This requires systematic elimination of waste, continuous improvement, and strategic planning.
Four Pillars of PPT Optimization
- Machine Readiness (Optimizing Availability & Performance – OEE Approach)
- Machines must be fully functional, well-maintained, and prepped before production starts.
- Offline preparation of programs, settings, and tooling should be prioritized.
- Preventive and predictive maintenance should be scheduled outside working hours to prevent breakdowns.
- Setup time reduction (SMED – Single-Minute Exchange of Dies) should be practiced to ensure quick changeovers.
- Once a machine starts production, it should run continuously until the job is completed.
- Material Readiness (Lean & TOC Perspective – Eliminating Waste & Bottlenecks)
- JIT (Just-in-Time) material flow should be ensured to avoid overstocking or shortages.
- Material should be organized in the exact sequence of operations to minimize motion waste.
- Material movement should be decoupled from machine operations to prevent unnecessary delays.
- Supervisory staff should ensure that the push system is in place. They should move the material to the next machine’s receiving area as soon as the previous operation is over. It can be achieved using additional helpers
- Documents and Instructions Readiness (Standardized Work – Lean Principle)
- All necessary documentation (drawings, work orders, SOPs) must be readily available before production begins.
- Standardized Work Procedures (SWP) should be enforced to ensure clarity and reduce errors.
- Digital instructions and visual management (e.g., Andon, Kanban systems) can reduce waiting time and improve workflow clarity.
- Right Workforce Allocation (Human Factor Optimization & Skills Alignment)
- Assigning the right personnel with the required skill set to each operation enhances efficiency.
- Cross-training workers (TWI – Training Within Industry) ensures workforce flexibility, reducing dependency on a single operator.
- Supervisors should proactively identify bottlenecks and potential disruptions before they impact production.
Conclusion
Making PPT a Universal Benchmark for Productivity
Maximizing Prime Productivity Time (PPT) requires synchronization of people, processes, and equipment to minimize waste and maximize value addition. While achieving 100% PPT is unrealistic, reducing non-value-adding activities to the lowest possible level should be the ultimate goal.
By implementing Lean principles, OEE measurement, and TOC-driven workflow optimization, PPT can become a universal metric for assessing and improving manufacturing productivity.
Why This Version is More Universally Accepted?
Ties into Proven Manufacturing Theories:
Lean (waste elimination)
OEE (machine & process optimization)
TOC (bottleneck removal)
Uses Established Terminology so that professionals can relate to it.
Incorporates Best Practices like JIT, SMED, Andon, Kanban, and Standardized Work Procedures to make it practical.
