The Boeing 767: From Concept to Production

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Modification during production

Benefits:

- All modification would be done during production and no parts would be installed only to be removed later. Meanwhile, production would continue on other sections of the plane.[pic 1]

- This was the traditional method of making engineering and design changes.

- All parts were installed only once. Configuration was more likely to remain secure.

- Moreover all activities would be controlled by normal management procedures, rather than by a separate program.

Drawbacks:

- The primary disadvantage was that the original production plan would be disrupted.

- Separate plans would have to be developed for the first thirty airplanes and all subsequent planes. Learning curves would be disrupted as well.

- Modification was expected to require approximately two million additional labour hours.

- Because all cockpit work would be deferred until engineering drawings and parts were available for two-crew models, test procedures would also change.

- Sequential testing would be impossible here because cockpit work would be deferred until complete plans and drawings were available.

- Functional testing would therefore have to be done after the two-person cockpit was fully installed. Problems might not be detected and corrected immediately and might well be hidden by systems making problem diagnosis much more difficult.

- Only when plans and parts were available for two-person cockpits, they would be incorporated within the flow of production.

Option chosen:

- The first plan has several advantages over the second one as even when there are some problems expected to arise in the first plan there are corresponding mitigation plans available to overcome them.

- Project delay: Also in the airframe industry delivery delay is unpardonable and hence the second option which requires almost twice as much labour hours is not feasible for the company. Also plans and parts for the two-person cock-pit are still not available which would mean more delay in project completion.

- Safety: both plans have some drawbacks and would require retesting to be done at a later stage. However in the second option it would be very difficult to detect any problems as they may be hidden in the system where problems can be easily diagnosed in the first case.

- # of Changes & learning effect drawback: Significant amount of changes would have to be made in the second plan and also learning effect cannot be leveraged in that case.

Although the managers are reserved about the first option it is the only feasible option available to help the company deliver it aircrafts on time and in proper condition