MANUFACTURING INDUSTRY

Types of inspection are:

1. Floor inspection 2. Centralized inspection

3. Combined inspection 4. Functional inspection

5. First piece inspection 6. Pilot piece inspection

7. Final inspection

1. FLOOR INSPECTION

In this system, the inspection is performed at the place of production. It suggests the checking of

materials in process at the machine or in the production time by patrolling inspectors. These

inspectors move from machine to machine and from one to the other work centres. Inspectors have

to be highly skilled. This method of inspection minimize the material handling, does not disrupt the

line layout of machinery and quickly locate the defect and readily offers field and correction.

Advantages

1. Detection of errors of the source reduces scrap and rework.

2. Correction is done before it affects further production, resulting in saving cost of

unnecessary work on defective parts.

3. Material handling time is reduced.

4. Job satisfaction to worker as he can’t be held responsible for bad work at a later date.

5. Greater number of pieces can be checked than a sample size.

6. Does not delay in production.

Disadvantages

1. Delicate instruments can be employed.

2. Measuring or inspection equipment have to be recalibrated often as they are subjected

to wear or dust.

3. High cost of inspection because of numerous sets of inspections and skilled inspectors.

4. Supervision of inspectors is difficult due to vibration.

5. Pressure on inspector.

6. Possibility of biased inspection because of worker.

Suitability

1. Heavy products are produced.

2. Different work centres are integrated in continuous line layout.

2. CENTRALISED INSPECTION

Inspection is carried in a central place with all testing equipment, sensitive equipment is housed

in air-conditioned area. Samples are brought to the inspection floor for checking. Centralised

inspection may locate in one or more places in the manufacturing indu

Advantages

1. Greater degree of inspection due to sensitive equipment.

2. Less number of inspectors and tools.

3. Equipment needs less frequency of recalibration.

4. Cost of inspection is reduced.

5. Unbiased inspection.

6. Supervision of inspectors made possible.

7. No distraction to the inspector.

Disadvantages

1. Defects of job are not revealed quickly for prevention.

2. Greater material handling.

3. High cost as products are subjected to production before they are prevented.

4. Greater delay in production.

5. Inspection of heavy work not possible.

6. Production control work is more complicated.

7. Greater scrap.

3. COMBINED INSPECTION

Combination of two methods whatever may be the method of inspection, whether floor or central.

The main objective is to locate and prevent defect which may not repeat itself in subsequent

operation to see whether any corrective measure is required and finally to maintain quality

economically.

4. FUNCTIONAL INSPECTION

This system only checks for the main function, the product is expected to perform. Thus an

electrical motor can be checked for the specified speed and load characteristics. It does not

reveal the variation of individual parts but can assure combined satisfactory performance of all

parts put together. Both manufacturers and purchasers can do this, if large number of articles

are needed at regular intervals. This is also called assembly inspection.

5. FIRST PIECE OR FIRST-OFF INSPECTIONS

First piece of the shift or lot is inspected. This is particularly used where automatic machines are

employed. Any discrepancy from the operator as machine tool can be checked to see that the

product is within in control limits. Excepting for need for precautions for tool we are check and

disturbance in machine set up, this yields good result if the operator is careful.

6. PILOT PIECE INSPECTION

This is done immediately after new design or product is developed. Manufacturer of product is done

either on regular shop floor if production is not disturbed. If production is affected to a large extent,

the product is manufactured in a pilot plant. This is suitable for mass production and products involving

large number of components such as automobiles aeroplanes etc., and modification are desi