ATT DEFINITY Communications System Generic 3 Basic Call Management System Instructions Manual

							Use of BCMS Rep orts for ACD Plannin g
6-26Issue  4  September 1995 
Table 6-8. 180 Seconds Average Service Time 
AVG SPEED ANS
agents 11 15 22 30 45 60 90 120 180
1222233345
2 111111121314161921
3 222324252629313539
4 353637394145485357
5 495152555762667276
6 646667717479849196
7 798183879197102110115
8 95 97 100 104 108 115 121 129 134
9 111 113 116 122 126 134 140 148 154
10 127 130 133 139 144 152 159 168 174
12 160 164 168 175 180 190 197 207 213
14 194 198 203 211 217 228 236 246 253
16 228 233 239 247 255 266 274 285 292
18 263 269 275 284 292 305 313 325 332
20 298 304 311 322 330 343 353 364 372
25 387 395 403 416 426 441 451 463 471
30 478 487 497 511 523 539 549 563 571
35 570 581 591 607 620 637 648 662 670
40 662 674 686 704 717 736 747 762 770
45 755 769 782 801 815 834 847 861 870
50 849 864 878 898 913 933 946 961 970
60 1038 1055 1071 1094 1110 1132 1145 1160 1169
70 1228 1247 1265 1290 1307 1330 1344 1360 1369
80 1419 1441 1460 1487 1505 1529 1543 1560 1569
90 1612 1635 1656 1684 1703 1728 1743 1759 1769
100 1804 1829 1852 1882 1902 1927 1942 1959 1968
125 2289 2318 2343 2377 2399 2425 2441 2459 2468
150 2776 2809 2837 2873 2896 2924 2940 2958 2968
175 3264 3301 3331 3369 3394 3423 3440 3458 3468
Continued on next page 
						

							Engineering  ACD Applications with Data Obtained from 
the BCMS Reports
Issue  4  September 1995
6-27
200 3755 3794 3826 3867 3892 3922 3939 3958 3968
225 4246 4288 4322 4365 4391 4421 4439 4458 4468
250 4738 4783 4819 4863 4890 4921 4938 4957 4967
275 5231 5278 5316 5361 5388 5420 5438 5457 5467
300 5724 5774 5813 5859 5887 5920 5938 5957 5967
350 6713 6766 6808 6857 6886 6919 6937 6957 6967
400 7703 7760 7804 7854 7885 7918 7937 7957 7967
450 8694 8754 8800 8853 8883 8918 8937 8957 8967
500 9686 9750 9797 9851 9882 9917 9936 9956 9967
550 10680 10745 10795 10850 10882 10917 10936 10956 10967
600 11673 11742 11792 11848 11881 11917 11936 11956 11967
650 12668 12738 12790 12847 12880 12916 12936 12956 12967
700 13662 13735 13788 13846 13880 13916 13936 13956 13967
750 14657 14732 14786 14845 14879 14916 14935 14956 14967
800 15653 15730 15785 15845 15879 15916 15935 15956 15967
850 16649 16727 16783 16844 16878 16915 16935 16956 16967
900 17645 17725 17782 17843 17878 17915 17935 17956 17967
950 18641 18723 18780 18842 18877 18915 18935 18956 18966
1000 19638 19721 19779 19842 19877 19915 19935 19956 19966
Table 6-8. 180 Seconds Average Service Time  — Continued
AVG SPEED ANS
agents 11 15 22 30 45 60 90 120 180
Continued on next page 
						

							Use of BCMS Rep orts for ACD Plannin g
6-28Issue  4  September 1995 
Table 6-9. 240 Seconds Average Service Time 
AVG SPEED ANS
agents 11 15 22 30 45 60 90 120 180
1222222233
28889910111214
3 161717181920222427
4 262727283032343740
5 363738404144465154
6 474849515357596468
7 586061636669737882
8 707173767883879297
9 828385889196100107111
10 94 96 98 101 104 110 114 121 126
12 118 121 123 127 131 137 142 150 155
14 143 146 149 154 158 165 171 179 185
16 169 172 175 181 186 194 200 208 214
18 195 198 202 208 213 222 229 238 244
20 221 225 229 235 241 251 258 267 273
25 287 292 297 305 312 323 331 341 348
30 354 360 366 376 383 395 404 415 422
35 422 429 436 447 456 469 478 490 497
40 491 499 506 518 528 542 552 564 571
45 561 569 577 590 601 616 626 638 646
50 630 639 649 663 674 689 700 713 721
60 771 781 792 808 820 837 849 862 870
70 912 924 936 954 967 986 998 1012 1020
80 1055 1068 1081 1101 1115 1134 1147 1161 1170
90 1198 1213 1227 1248 1263 1283 1296 1311 1320
100 1341 1358 1373 1395 1411 1432 1445 1461 1469
125 1702 1722 1740 1765 1782 1805 1819 1835 1844
150 2065 2088 2108 2136 2155 2179 2193 2210 2219
175 2430 2455 2477 2507 2527 2552 2567 2584 2593
Continued on next page 
						

							Engineering  ACD Applications with Data Obtained from 
the BCMS Reports
Issue  4  September 1995
6-29
200 2796 2823 2847 2879 2900 2926 2942 2959 2968
225 3162 3192 3218 3251 3273 3300 3316 3334 3343
250 3530 3562 3589 3624 3647 3675 3691 3708 3718
275 3898 3932 3961 3997 4021 4049 4065 4083 4093
300 4267 4302 4332 4370 4394 4423 4440 4458 4468
350 5005 5045 5077 5117 5142 5172 5189 5208 5218
400 5746 5788 5822 5865 5891 5922 5939 5958 5968
450 6487 6532 6568 6612 6639 6671 6688 6707 6717
500 7229 7277 7315 7360 7388 7420 7438 7457 7467
550 7972 8022 8062 8109 8137 8170 8188 8207 8217
600 8715 8768 8809 8857 8886 8919 8937 8957 8967
650 9459 9514 9557 9606 9635 9669 9687 9707 9717
700 10204 10261 10304 10355 10385 10418 10437 10457 10467
750 10949 11007 11052 11104 11134 11168 11187 11207 11217
800 11694 11754 11800 11853 11883 11918 11937 11957 11967
850 12440 12502 12549 12602 12633 12668 12686 12706 12717
900 13186 13249 13297 13351 13382 13417 13436 13456 13467
950 13932 13997 14045 14100 14132 14167 14186 14206 14217
1000 14678 14744 14794 14849 14881 14917 14936 14956 14967
Table 6-9. 240 Seconds Average Service Time  — Continued
AVG SPEED ANS
agents 11 15 22 30 45 60 90 120 180
Continued on next page 
						

							Use of BCMS Rep orts for ACD Plannin g
6-30Issue  4  September 1995 
Table 6-10. 300 Seconds Average Service Time 
AVG SPEED ANS
agents 11 15 22 30 45 60 90 120 180
1111112222
26677788910
3 131313141415161820
4 212121222324262830
5 292930313234363941
6 373839404144464952
7 464748505154566063
8 565657596164677175
9 656667697175788386
10 74 76 77 79 81 85 89 94 98
12 94 95 97 100 102 107 111 117 121
14 114 116 117 121 124 129 133 140 144
16 134 136 138 142 145 151 156 163 168
18 155 157 159 164 167 174 179 186 191
20 175 178 181 185 189 196 202 210 215
25 228 231 235 240 245 253 260 268 274
30 281 285 289 296 302 311 318 327 333
35 336 340 345 352 359 369 377 387 393
40 390 395 401 409 416 427 435 446 453
45 445 451 457 466 474 486 494 505 512
50 501 507 513 524 532 545 554 565 572
60 612 620 627 639 649 662 672 684 691
70 725 734 742 755 766 781 791 804 811
80 838 848 857 872 883 899 910 923 931
90 952 963 973 989 1001 1018 1029 1043 1050
100 1067 1078 1089 1106 1119 1137 1148 1162 1170
125 1354 1368 1381 1401 1415 1434 1447 1461 1470
150 1643 1659 1675 1696 1712 1733 1746 1761 1769
175 1934 1952 1969 1992 2009 2031 2045 2060 2069
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							Engineering  ACD Applications with Data Obtained from 
the BCMS Reports
Issue  4  September 1995
6-31
200 2225 2245 2264 2289 2307 2330 2344 2360 2369
225 2518 2539 2559 2586 2605 2629 2643 2660 2669
250 2811 2834 2855 2884 2904 2928 2943 2959 2969
275 3104 3129 3152 3182 3202 3227 3242 3259 3268
300 3398 3425 3449 3480 3501 3527 3542 3559 3568
350 3987 4017 4043 4076 4098 4125 4141 4159 4168
400 4578 4610 4638 4674 4697 4724 4741 4758 4768
450 5170 5204 5234 5271 5295 5324 5340 5358 5368
500 5762 5799 5830 5869 5894 5923 5940 5958 5968
550 6355 6394 6427 6467 6492 6522 6539 6558 6568
600 6948 6990 7024 7065 7091 7122 7139 7158 7168
650 7543 7586 7621 7664 7690 7721 7739 7757 7767
700 8137 8182 8219 8262 8290 8321 8338 8357 8367
750 8732 8779 8816 8861 8889 8920 8938 8957 8967
800 9327 9376 9414 9460 9488 9520 9538 9557 9567
850 9923 9973 10012 10059 10087 10120 10138 10157 10167
900 10518 10570 10610 10658 10687 10719 10738 10757 10767
950 11114 11167 11209 11257 11286 11319 11337 11357 11367
1000 11711 11765 11807 11856 11886 11919 11937 11957 11967
Table 6-10. 300 Seconds Average Service Time  — Continued
AVG SPEED ANS
agents 11 15 22 30 45 60 90 120 180
Continued on next page 
						

							Use of BCMS Rep orts for ACD Plannin g
6-32Issue  4  September 1995 
Table 6-11. 600 Seconds Average Service Time 
AVG SPEED ANS
agents 11 15 22 30 45 60 90 120 180
1111111111
2333334445
3667777889
4 101011111111121314
5 141415151516171819
6 191919192021222325
7 232324242526272830
8 282828293030323336
9 323233343536373941
10 37 37 38 38 40 41 43 44 47
12 47 47 48 48 50 51 53 55 58
14 56 57 58 59 60 62 64 67 70
16 66 67 68 69 71 73 76 78 81
18 77 77 78 80 82 84 87 89 93
20 87 88 89 90 93 95 98 101 105
25 113 114 116 117 120 123 127 130 134
30 140 141 143 145 148 151 156 159 164
35 166 168 170 172 176 179 185 188 193
40 194 195 198 200 205 208 214 218 223
45 221 223 226 228 233 237 243 247 253
50 248 250 254 257 262 266 272 277 282
60 304 306 310 314 320 324 331 336 342
70 360 363 367 371 378 383 390 395 402
80 416 419 424 429 436 442 450 455 461
90 473 476 482 487 495 501 509 514 521
100 530 533 539 545 553 560 568 574 581
125 672 677 684 691 700 708 717 723 731
150 816 822 830 837 848 856 866 873 880
175 961 967 977 984 996 1005 1016 1022 1030
Continued on next page 
						

							Engineering  ACD Applications with Data Obtained from 
the BCMS Reports
Issue  4  September 1995
6-33
200 1106 1113 1123 1132 1145 1154 1165 1172 1180
225 1251 1259 1270 1280 1293 1303 1314 1322 1330
250 1397 1405 1418 1428 1442 1452 1464 1471 1480
275 1543 1552 1565 1576 1591 1601 1614 1621 1630
300 1690 1699 1713 1724 1740 1750 1763 1771 1780
350 1983 1994 2010 2021 2038 2049 2063 2071 2079
400 2277 2289 2306 2319 2337 2348 2362 2370 2379
450 2572 2585 2603 2617 2636 2648 2662 2670 2679
500 2867 2881 2901 2915 2934 2947 2961 2970 2979
550 3163 3177 3198 3213 3234 3246 3261 3270 3279
600 3459 3474 3496 3512 3533 3546 3561 3569 3579
650 3755 3771 3794 3811 3832 3845 3861 3869 3879
700 4051 4069 4092 4109 4131 4145 4160 4169 4179
750 4348 4366 4391 4408 4431 4444 4460 4469 4479
800 4645 4664 4689 4707 4730 4744 4760 4769 4779
850 4942 4961 4988 5006 5029 5044 5060 5069 5079
900 5239 5259 5286 5305 5329 5343 5360 5369 5378
950 5536 5557 5585 5604 5629 5643 5660 5669 5678
1000 5834 5855 5884 5904 5928 5943 5959 5969 5978
1 154 195 253 302 359 392 429 449 470
2 575 648 736 799 865 902 942 962 984
3 1044 1135 1237 1305 1376 1415 1455 1476 1498
4 1531 1633 1743 1815 1888 1928 1969 1990 2012
5 2025 2136 2251 2326 2401 2441 2483 2504 2526
6 2525 2641 2761 2838 2914 2955 2997 3018 3040
Table 6-11. 600 Seconds Average Service Time  — Continued
AVG SPEED ANS
agents 11 15 22 30 45 60 90 120 180
Continued on next page 
						

							Use of BCMS Rep orts for ACD Plannin g
6-34Issue  4  September 1995 
Trunk Engineering Guidelines
The number of trunks required for a typical ACD ranges from 1.1 to 1.7 times the 
number of agents (whenever a blocked call represents potential lost revenue). 
As in the case of agents, the number of trunks required for an ACD is based on 
the incoming traffic to each split, not the ACD as a whole.
The left-most column in Table 6-12 lists the number of trunks required to service 
a split depending on the carried load in 
Erlangs and the blocking probability. 
Erlang is a unit of traffic intensity, or load, used to express the amount of traffic it 
takes to keep one facility busy for one hour. Bloc king probability relates to the 
desired grade of service. The possible blocking probabilities are shown across 
the top  of Table 6-12, and the entries under the blocking probabilities are c arried 
loads in Erlangs.
To determine the number of trunks needed for a given split, use Table 6-12 as 
follows:
nYou will need a sp lit report for the peak busy-hour (for example, list 
bcms split ## time xx:xx xx:xx) for the busiest day of the week.
NOTE:
If the time interval is suffic iently long  to cover the busiest hours of the 
day (such as 8:00 to 18:00) you need only scan the report to 
determine which hour is the busy hour. If you have this report for a 
time other than the peak busy hour then you will need to estimate 
values for the busy hour.
nFor the identified peak busy hour, you will need to determine the AVG 
TALK TIME and the AVG SPEED ANS. Otherwise, you must estimate the 
average call duration: the total time a caller spends waiting for an answer, 
plus any time on hold (in queue), and plus the service time (the time the 
caller spends talking to an agent).
nIf you know the calling volume, otherwise referred to as the  busy-hour 
calls, then use that value. As an alternative, you must estimate the number 
of busy hour calls received by the ACD split during peak levels of caller 
activity.
NOTE:
The calling volume is simply the sum of the two fields (# ACD and # 
ABAND) for the identified busy hour. This does not include:
ncalls never queued
ncalls given Central Office (CO) busy
nMultiply the call duration (in fractions of an hour) by the rate of busy-hour 
calls (in calls per hour).  This number is the carried load in Erlangs. 
Abandoned calls should be multiplied by the AVG ABAND time. 
						

							Engineering  ACD Applications with Data Obtained from 
the BCMS Reports
Issue  4  September 1995
6-35
nDetermine the desired grade of service (the blocking probability).  The 
blocking probability for each split is defined as the ratio of blo cked calls to 
the total number of incoming calls.
nIn the column corresponding to the desired grade of service, (for 
example, 1 percent blocking probability) choose the nearest higher 
carried load.  The number of trunks required is then read from the 
left-most column.
NOTE:
The entries in Table 6-12 are offered loads in Erlangs.
Example 4:
An insurance agency has an ACD that queues calls incoming from the public 
switched network. The agency knows that the average caller spend s 30 seconds 
on hold (in queue), and requires 6 minutes and 20 seconds to service.  The 
busy-hour call arrival rate is 70 per hour. How many trunks d oes the agency need 
to provide a service level of 99 percent (1 percent blocking probability)?
The average call duration is:
Therefore, the carried load in Erlangs is:
Under the 1 percent column, you will find that 14 trunks can service a carried 
load of 7.278 Erlang s while 16 trunks can service 8.786 Erlangs.  Interpolate as 
follows:
Therefore, the agency will need 15 trunks to satisfy its customers.
average call duration=30+380=410seconds or0. 11389hours
carried load=0. 11389´70=7. 972
y=number o f  trunks
y=y
0+(y1-y0)
x1-x0
x-x0_ _______
y=14+( 16-14 )
8. 786-7. 278 7. 972-7. 278
_____________
y=14+( 2´0. 460 )
y=14. 92