Downloaded from https://www.everyspec.com -M N3 well es that of producing it. Each of thes qua- The fuze designer-ike the designer of any tities is, in itsf, a complex combination of di, other component in a weapon system-must be vers factors which may include aspects of te thoroughly familiar with the basis for the stated tistics, milit strary q and tactics, and al requirements. He then is in a position to evaluate branches of engineering.
the rquirements and, if indicated, to give an in- The process of compeing alternative solu- Wlbint proposal to relax those requirements tions to stated requirements in terms of the that would be too difficult, time-consuming, or value received (effectiveness) for the resource costly to achieve. The relcting of requirements expended (costs) is called the Cost/Effectiveness is called trade-off. analysis. The primary ingredients of this analy. By direction, new weapon systems must pro- sis w: vide more than marginal improvements over (1) Objective(s) existing systems.
The improvement may be in (2) Alternative means or systems the ao of incresd effectiveness, reliability, (3) Costs or resources required for each safety, or capability not achieved by an existing system system. It could now happen, for example, that (4) A mathematical or logical model, a set the improvements of a particular new system of relations among the objectives, alteratve may be significant despite failure to accom- means, environment, and resources plish all of the deslgn objectveL This would be (5) A set of criteria for choosing the pr- a valuable bit of information if a proposed ferred alternatives usually relating objectives and trade-off is deemed desirable.
cost& An example of this might be the development The objective is the establishment of the al- of a projectile and fuze for a new weapon. Both ternatives among which it is possible to choose. gun an projectile development are on schedule. Alternatives that can achieve the objectives must During testing, it is determined that the fuse is be defined and cost or resource consequences not operable after vacuum-sten pressure tests. must be attached to each of the alternative Suppose that existing fues in the field were also means. not capable of pusing this test.
The time required In the course of performing the analysis, each to redesign the fuze would delay the delivery of alternative is related to the objective through the new weapon into the field. In this case, "*t a form of intellectual exercise that can be would be logical to propose that the vacuum- called a mdeI or a set of caleciona. Basically, steam pressure requirement for the fuze be a choice must be made between maximizing ac- waived. complishment of the objective for a given cost Note that MIL-S-D tests are not mandatory or minimizing the cost for achieving a given for all applications (see par. 15-5).
Being aware objective' 3 that fuzes off the shelf or presently in produc- tion may not meet all of the Military Standards 2-3 SAFETY AND RELIABILITY for one reason or another, the good fuze de- signer judiciously reruns all of his necessary de- Considerations of safety and reliability cannot velopment tests even though lie is using avail- be separated. The fuze must function as in- able components. tended (reliability) but must not function under all but the right conditions (safety).
2-1.3 DESIGN TRADE-OFFS cides the cost of delivering it to its target as Reliability is a measure of the extent to which 2-2 ECONOMICS a device performs as it was designed to perform during the usually short period between launch- The assessment of a weapon system involves ing and completion of its mission. Obviously, re- the comparison of its value with its cost. The liability of ammunition and of its components is value per round may-\ be considered to be the of key importance. Weapons are useless if they product of the military value of the damage of don't function as intended.
which a round of ammunition is capable and the Safety is a basic consideration throughout probability that a given round will inflict this item life. We are concerned with the extent to damage. The cost of a round of ammunition in- which a device can possibly be made to operate 2-2