Industrial & Production Engineering Mock Interview Questions & Practice

What is the difference between an operation and an inspection in process charting symbols?

Key points to cover:

• Operation: an activity that changes, adds to, or prepares an item
• E.g. assembling, machining
• Inspection: checking an item against a standard without changing it

What is performance rating in time study, and why is it necessary?

Key points to cover:

• Comparing an observed worker's pace/effectiveness
• To a defined "normal" pace
• Different workers work at different speeds, needs a fair adjustment

What is a musculoskeletal disorder (MSD) in the context of occupational ergonomics, and what commonly causes it?

Key points to cover:

• An injury/disorder affecting muscles, tendons, nerves, or joints
• Often developing gradually
• Commonly caused by repetitive motion, awkward postures, excessive force

What is the feasible region in a linear programming problem, and what does it represent geometrically?

Key points to cover:

• The set of all points satisfying all constraints simultaneously
• Represents a region
• Often a polygon in two dimensions bounded by the constraint lines

What is the difference between a single-server and a multi-server queuing system?

Key points to cover:

• Single-server: only one server processing customers
• Multi-server: multiple parallel servers
• Generally reduces average waiting time for the same arrival rate

What is slack (or float) in project scheduling, and what does it indicate about a non-critical activity?

Key points to cover:

• The amount of time an activity can be delayed
• Without delaying overall project completion
• Indicates scheduling flexibility for that activity

What is the difference between aggregate production planning and detailed (master) production scheduling?

Key points to cover:

• Aggregate: overall production levels, workforce, inventory
• At a broad, product-family level over a medium-term horizon
• Master scheduling breaks this into specific quantities and timing

What is the Economic Order Quantity (EOQ) model, and what does it determine?

Key points to cover:

• The optimal order quantity minimizing total ordering + holding cost
• Balances ordering costs (favor larger orders)
• Against holding costs (favor smaller, more frequent orders)

What is lead time in the context of MRP, and how is it used in scheduling material orders?

Key points to cover:

• The time between initiating an order and having material available
• Used by MRP to work backward from a required date
• Determines when an order must be placed/started

What are upper and lower control limits on a control chart, and how are they typically determined?

Key points to cover:

• Boundaries beyond which a process is "out of control"
• Typically at plus/minus three standard deviations from the mean
• Based on the natural variation observed when operating normally

What is the Define phase of DMAIC primarily concerned with?

Key points to cover:

• Clearly defining the problem, project goals, scope
• And customer requirements
• Establishes a clear foundation for the rest of the project

What is ISO 9001, and what does it certify about an organization?

Key points to cover:

• An internationally recognized quality management system standard
• Certifies a documented, consistent quality management system
• Doesn't certify the quality of any specific product itself

What is the difference between hot working and cold working in metal forming processes?

Key points to cover:

• Hot working: above the material's recrystallization temperature
• Allows significant deformation without work hardening
• Cold working: below recrystallization, results in work hardening

What is cutting speed in machining, and how does it affect tool life and surface finish?

Key points to cover:

• The relative velocity between cutting tool and workpiece surface
• Higher speeds increase material removal rate
• Can reduce tool life due to increased heat generation

What is the difference between MIG (GMAW) and TIG (GTAW) welding?

Key points to cover:

• MIG uses a continuously fed consumable wire electrode
• Plus a shielding gas
• TIG uses a non-consumable tungsten electrode with a separate filler rod