ME or MEng Master of Engineering Master of Engineering Computer-Aided Manufacturing 5 â Questions and Answers
Question 1: Which scheduling algorithm minimizes the maximum lateness of jobs in a single-machine manufacturing environment?
- Shortest Processing Time (SPT)
- Earliest Due Date (EDD) (Correct answer)
- First Come First Served (FCFS)
- Longest Processing Time (LPT)
Correct answer: Earliest Due Date (EDD)
The Earliest Due Date (EDD) rule minimizes maximum lateness by sequencing jobs in order of their due dates.
Question 2: In the context of machine tool metrology, what is the Abbe principle (Abbe error)?
- Measurement error due to thermal expansion of the workpiece
- Error amplification when the measurement axis is offset from the reference axis (Correct answer)
- Systematic error caused by non-linearity of encoders
- Uncertainty introduced by stylus contact force
Correct answer: Error amplification when the measurement axis is offset from the reference axis
Abbe's principle states that angular errors are amplified into linear errors proportional to the offset distance between the measured and reference axes.
Question 3: What is the primary function of a Manufacturing Execution System (MES) in a smart factory?
- Designing product geometry and toolpaths
- Bridging ERP business planning with real-time shop floor control and data collection (Correct answer)
- Managing supplier contracts and procurement
- Generating financial reports from production data
Correct answer: Bridging ERP business planning with real-time shop floor control and data collection
MES sits between ERP systems and machine-level controls, tracking WIP, enforcing schedules, and collecting real-time production data.
Question 4: In EDM (Electrical Discharge Machining), material removal occurs through which mechanism?
- Mechanical abrasion by an abrasive-coated wire
- Thermal erosion by repeated electrical sparks in a dielectric fluid (Correct answer)
- Chemical dissolution by electrolytic action
- High-pressure water jet erosion
Correct answer: Thermal erosion by repeated electrical sparks in a dielectric fluid
EDM removes material through controlled electrical discharges that locally melt and vaporize the workpiece in a dielectric fluid.
Question 5: Which topology optimization method is most commonly integrated with CAD/CAM software to reduce part weight while maintaining structural performance?
- Parametric sweep optimization
- Solid Isotropic Material with Penalization (SIMP) (Correct answer)
- Taguchi method
- Monte Carlo simulation
Correct answer: Solid Isotropic Material with Penalization (SIMP)
SIMP iteratively redistributes material density within a design space, penalizing intermediate densities to produce distinct solid/void regions.
Question 6: In CNC turning, which parameter most directly controls the surface roughness (Ra) of a turned part?
- Depth of cut
- Feed rate per revolution (Correct answer)
- Spindle power
- Coolant flow rate
Correct answer: Feed rate per revolution
Surface roughness in turning is primarily determined by feed rate and tool nose radius through the kinematic roughness formula Ra â f²/8r.
Question 7: What is the purpose of 'fixtureless manufacturing' enabled by adaptive machining and in-process measurement?
- Eliminating all CNC programs by using manual machining
- Allowing parts to be machined without dedicated fixtures by measuring and compensating for part position in real time (Correct answer)
- Replacing cutting tools with laser ablation
- Using robots to hold parts instead of vises
Correct answer: Allowing parts to be machined without dedicated fixtures by measuring and compensating for part position in real time
Adaptive machining measures actual part position and updates toolpaths in real time, reducing reliance on precise physical fixtures.
ME or MEng Master of Engineering Master of Engineering Computer-Aided Manufacturing 5
Which scheduling algorithm minimizes the maximum lateness of jobs in a single-machine manufacturing environment?