What safety stock should Ron Satterfield Corporation maintain if mean sales are 80 during the reorder period, the standard deviation is 7, and Ron can tolerate stockouts 10% of the time?
What safety stock should Ron Satterfield Corporation maintain if mean sales are 80 during the reorder period, the standard deviation is 7, and Ron can tolerate stockouts 10% of the time?
From Appendix I, Z at an area of .9 (or 1 – .10) = 1.28, and Equation (12-14):
Safety stock = Z\sigma_{dLT}
= 1.28(7) = 8.96 units, or 9 units
TABLE I.1 | ||||||||||
Z | .00 | .01 | .02 | .03 | .04 | .05 | .06 | .07 | .08 | .09 |
.0 | .50000 | .50399 | .50798 | .51197 | .51595 | .51994 | .52392 | .52790 | .53188 | .53586 |
.1 | .53983 | .54380 | .54776 | .55172 | .55567 | .55962 | .56356 | .56749 | .57142 | .57535 |
.2 | .57926 | .58317 | .58706 | .59095 | .59483 | .59871 | .60257 | .60642 | .61026 | .61409 |
.3 | .61791 | .62172 | .62552 | .62930 | .63307 | .63683 | .64058 | .64431 | .64803 | .65173 |
.4 | .65542 | .65910 | .66276 | .66640 | .67003 | .67364 | .67724 | .68082 | .68439 | .68793 |
.5 | .69146 | .69497 | .69847 | .70194 | .70540 | .70884 | .71226 | .71566 | .71904 | .72240 |
.6 | .72575 | .72907 | .73237 | .73565 | .73891 | .74215 | .74537 | .74857 | .75175 | .75490 |
.7 | .75804 | .76115 | .76424 | .76730 | .77035 | .77337 | .77637 | .77935 | .78230 | .78524 |
.8 | .78814 | .79103 | .79389 | .79673 | .79955 | .80234 | .80511 | .80785 | .81057 | .81327 |
.9 | .81594 | .81859 | .82121 | .82381 | .82639 | .82894 | .83147 | .83398 | .83646 | .83891 |
1.0 | .84134 | .84375 | .84614 | .84849 | .85083 | .85314 | .85543 | .85769 | .85993 | .86214 |
1.1 | .86433 | .86650 | .86864 | .87076 | .87286 | .87493 | .87698 | .87900 | .88100 | .88298 |
1.2 | .88493 | .88686 | .88877 | .89065 | .89251 | .89435 | .89617 | .89796 | .89973 | .90147 |
1.3 | .90320 | .90490 | .90658 | .90824 | .90988 | .91149 | .91309 | .91466 | .91621 | .91774 |
1.4 | .91924 | .92073 | .92220 | .92364 | .92507 | .92647 | .92785 | .92922 | .93056 | .93189 |
1.5 | .93319 | .93448 | .93574 | .93699 | .93822 | .93943 | .94062 | .94179 | .94295 | .94408 |
1.6 | .94520 | .94630 | .94738 | .94845 | .94950 | .95053 | .95154 | .95254 | .95352 | .95449 |
1.7 | .95543 | .95637 | .95728 | .95818 | .95907 | .95994 | .96080 | .96164 | .96246 | .96327 |
1.8 | .96407 | .96485 | .96562 | .96638 | .96712 | .96784 | .96856 | .96926 | .96995 | .97062 |
1.9 | .97128 | .97193 | .97257 | .97320 | .97381 | .97441 | .97500 | .97558 | .97615 | .97670 |
2.0 | .97725 | .97784 | .97831 | .97882 | .97932 | .97982 | .98030 | .98077 | .98124 | .98169 |
2.1 | .98214 | .98257 | .98300 | .98341 | .98382 | .98422 | .98461 | .98500 | .98537 | .98574 |
2.2 | .98610 | .98645 | .98679 | .98713 | .98745 | .98778 | .98809 | .98840 | .98870 | .98899 |
2.3 | .98928 | .98956 | .98983 | .99010 | .99036 | .99061 | .99086 | .99111 | .99134 | .99158 |
2.4 | .99180 | .99202 | .99224 | .99245 | .99266 | .99286 | .99305 | .99324 | .99343 | .99361 |
2.5 | .99379 | .99396 | .99413 | .99430 | .99446 | .99461 | .99477 | .99492 | .99506 | .99520 |
2.6 | .99534 | .99547 | .99560 | .99573 | .99585 | .99598 | .99609 | .99621 | .99632 | .99643 |
2.7 | .99653 | .99664 | .99674 | .99683 | .99693 | .99702 | .99711 | .99720 | .99728 | .99736 |
2.8 | .99744 | .99752 | .99760 | .99767 | .99774 | .99781 | .99788 | .99795 | .99801 | .99807 |
2.9 | .99813 | .99819 | .99825 | .99831 | .99836 | .99841 | .99846 | .99851 | .99856 | .99861 |
3.0 | .99865 | .99869 | .99874 | .99878 | .99882 | .99886 | .99889 | .99893 | .99896 | .99900 |
3.1 | .99903 | .99906 | .99910 | .99913 | .99916 | .99918 | .99921 | .99924 | .99926 | .99929 |
3.2 | .99931 | .99934 | .99936 | .99938 | .99940 | .99942 | .99944 | .99946 | .99948 | .99950 |
3.3 | .99952 | .99953 | .99955 | .99957 | .99958 | .99960 | .99961 | .99962 | .99964 | .99965 |
3.4 | .99966 | .99968 | .99969 | .99970 | .99971 | .99972 | .99973 | .99974 | .99975 | .99976 |
3.5 | .99977 | .99978 | .99978 | .99979 | .99980 | .99981 | .99981 | .99982 | .99983 | .99983 |
3.6 | .99984 | .99985 | .99985 | .99986 | .99986 | .99987 | .99987 | .99988 | .99988 | .99989 |
3.7 | .99989 | .99990 | .99990 | .99990 | .99991 | .99991 | .99992 | .99992 | .99992 | .99992 |
3.8 | .99993 | .99993 | .99993 | .99994 | .99994 | .99994 | .99994 | .99995 | .99995 | .99995 |
3.9 | .99995 | .99995 | .99996 | .99996 | .99996 | .99996 | .99996 | .99996 | .99997 | .99997 |
TABLE I.2 | ||||||||||
Z | .00 | .01 | .02 | .03 | .04 | .05 | .06 | .07 | .08 | .09 |
0.0 | .00000 | .00399 | .00798 | .01197 | .01595 | .01994 | .02392 | .02790 | .03188 | .03586 |
0.1 | .03983 | .04380 | .04776 | .05172 | .05567 | .05962 | .06356 | .06749 | .07142 | .07535 |
0.2 | .07926 | .08317 | .08706 | .09095 | .09483 | .09871 | .10257 | .10642 | .11026 | .11409 |
0.3 | .11791 | .12172 | .12552 | .12930 | .13307 | .13683 | .14058 | .14431 | .14803 | .15173 |
0.4 | .15542 | .15910 | .16276 | .16640 | .17003 | .17364 | .17724 | .18082 | .18439 | .18793 |
0.5 | .19146 | .19497 | .19847 | .20194 | .20540 | .20884 | .21226 | .21566 | .21904 | 22240 |
0.6 | .22575 | .22907 | .23237 | .23565 | .23891 | .24215 | .24537 | .24857 | .25175 | .25490 |
0.7 | .25804 | .26115 | .26424 | .26730 | .27035 | .27337 | .27637 | .27935 | .28230 | .28524 |
0.8 | .28814 | .29103 | .29389 | .29673 | .29955 | .30234 | .30511 | .30785 | .31057 | .31327 |
0.9 | .31594 | .31859 | .32121 | .32381 | .32639 | .32894 | .33147 | .33398 | .33646 | .33891 |
1.0 | .34134 | .34375 | .34614 | .34850 | .35083 | .35314 | .35543 | .35769 | .35993 | .36214 |
1.1 | .36433 | .36650 | .36864 | .37076 | .37286 | .37493 | .37698 | .37900 | .38100 | .38298 |
1.2 | .38493 | .38686 | .38877 | .39065 | .39251 | .39435 | .39617 | .39796 | .39973 | .40147 |
1.3 | .40320 | .40490 | .40658 | .40824 | .40988 | .41149 | .41309 | .41466 | .41621 | .41174 |
1.4 | .41924 | .42073 | .42220 | .42364 | .42507 | .42647 | .42786 | .42922 | .43056 | .43189 |
1.5 | .43319 | .43448 | .43574 | .43699 | .43822 | .43943 | .44062 | .44179 | .44295 | .44408 |
1.6 | .44520 | .44630 | .44738 | .44845 | .44950 | .45053 | .45154 | .45254 | .45352 | .45449 |
1.7 | .45543 | .45637 | .45728 | .45818 | .45907 | .45994 | .46080 | .46164 | .46246 | .46327 |
1.8 | .46407 | .46485 | .46562 | .46638 | .46712 | .46784 | .46856 | .46926 | .46995 | .47062 |
1.9 | .47128 | .47193 | .47257 | .47320 | .47381 | .47441 | .47500 | .47558 | .47615 | .47670 |
2.0 | .47725 | .47778 | .47831 | .47882 | .47932 | .47982 | .48030 | .48077 | .48124 | .48169 |
2.1 | .48214 | .48257 | .48300 | .48341 | .48382 | .48422 | .48461 | .48500 | .48537 | .48574 |
2.2 | .48610 | .48645 | .48679 | .48713 | .48745 | .48778 | .48809 | .48840 | .48870 | .48899 |
2.3 | .48928 | .48956 | .48983 | .49010 | .49036 | .49061 | .49086 | .49111 | .49134 | .49158 |
2.4 | .49180 | .49202 | .49224 | .49245 | .49266 | .49286 | .49305 | .49324 | .49343 | .49361 |
2.5 | .49379 | .49396 | .49413 | .49430 | .49446 | .49461 | .49477 | .49492 | .49506 | .49520 |
2.6 | .49534 | .49547 | .49560 | .49573 | .49585 | .49598 | .49609 | .49621 | .49632 | .49643 |
2.7 | .49653 | .49664 | .49674 | .49683 | .49693 | .49702 | .49711 | .49720 | .49728 | .49736 |
2.8 | .49744 | .49752 | .49760 | .49767 | .49774 | .49781 | .49788 | .49795 | .49801 | .49807 |
2.9 | .49813 | .49819 | .49825 | .49831 | .49836 | .49841 | .49846 | .49851 | .49856 | .49861 |
3.0 | .49865 | .49869 | .49874 | .49878 | .49882 | .49886 | .49889 | .49893 | .49897 | .49900 |
3.1 | .49903 | .49906 | .49910 | .49913 | .49916 | .49918 | .49921 | .49924 | .49926 | .49929 |