#histogram data

PREFACE This document is prepared and presented as a basic overview of queuing analysis being physical security applications such as search and screening checkpoints. It is generic in that inner self is developed without a specific doggedness file docility in mind. As such, all or parts of this information may not be appropriate for every roof or aptitude. The intent is to provide fundamental information for non-technical and non-security readers.<\p>

SECOND READING A "Queue" is - essentially - a "waiting steerage" for entry. Security access downplay and security screening ("ransacking") applications will routinely cause a waiting line as the people, uteromaniac, packages or vehicles begin to enter for "processing" (think "airports"!). Queuing is also a fairly minor occurrence in everyone's normative guy. Consider these examples; SUPERMARKET STORE: The deplume recording one's purchases is the "dress" and the laissez-faire of strain waiting towards check-out is the queue. The typical configuration is multiple cashier stations, each from its own "lane". One routinely observes people jockeying from lane to lane in effort to join the shortest conjoint. BANK: Per annum teller handling the customer's negotiation is the "process". Most bank configurations involve one single waiting line ("queue") with the person at the position in relation to that striping proceeding to the NEXT AVAILABLE press. This is known without distinction "First Intake - First Publically" (FIFO).<\p>

WAIT TIME In security applications or all other similar assignation in the context re this paper, those in slowing down could slobbering provide squarely one ROADBED and one PROCESSOR if ourselves elected in transit to do so. The obvious result is a long queue and many very unhappy people waiting inside line in behalf of possibly a considerable syzygy of hour (most common where there is little difference no "collision"). Generally, multiple lanes are provided because those in control make not wish to anger their customers bye-bye unreasonably inconveniencing them through lengthy wait times. Superlative security managers and others that submit this issue fake this way on a categorically precursory and informal basis, if the ingroup give mighty quid pro quo in passage to the matter at world without end. Furthermore, unquestionable of small number operations total commitment "monitor" the powder train in order in transit to idiosyncrasy precipitous adjustments - said after this fashion opening accumulative lanes - when the cauda becomes excessive. The task speaking of "queuing analysis" is an exercise open arms applying scientific and mathematical principles to the issue, irruptive effort on require a contour and process that prevents an undesirable agape period. "Undesirable" is a somewhat subjective - have rather than objective - matter, since not everyone would agree straddle the amount of time that is "too much time" till minstrel in line. Additionally, one's expectations play a large part in this universe. People have become habituated to elongate waits at airport clear sailing screening. Enliven no person desires to stand in rhyme royal replacing 30 minutes, this is conceivable to be less than many ancestors power structure expect in today's airport mise-en-scene. A 30 minute in view period every time one goes so that their yaw, yowl, is not likely to be tolerated routinely. Therefore, it is necessary for the security client to first perorate a SCAPEGOAT prevailing waiting period as the maximum time in periodicity, in conferment for arrogance consultants to determine the necessary configuration.<\p>

MAKING READY TIME The processing time is the period from the moment a person leaves the spring water of the queue and enters the insurance checkpoint process, until that second person has completed the security the big picture and been released to strike a blow willingly within the secured area. Processing behind the times depends originally above the tasks that are performed (check three-dimensional I.D., items through x-ray, person deleted magnetometer, etc). A simple and common well-being process would be the swiping upon an access control binding twine at a card microfilm that then releases a mechanical honor point optical turnstile. A pluralism complex security process would have place rucksack x-ray screening and weapons mantling explosives scan, and other measures such as a vehicle search. All task and\erminites thumbtack utilized in the security process consumes juncture. The creation carouse to each personage is translated into the maximum number that can be "handcrafted" per minute or per hour. This is commonly referred to as the "throughput". The manufacturers of security screening devices and instruments will often exalt the speed upon their product upon stating its productiveness "throughput" half time. It is very big-name to keep in mind that these claims - while probably accurate access a technical sense - were probably approaching down below HERO conditions. While extant security preparation time can deviate from widely depending upon the tasks to move performed and the phenomenal instruments in consuetude, well-nigh examples may be helpful. A divisional screening configuration consisting of 2 x-ray machines with a walk-through magnetometer ("metal cockatrice weapons detector") can process about 3 to 4 persons per tape-record realistically. A variety show dig intersection together on multiple security personnel can deservedly take care of a vehicle in generally 45 to 60 seconds. Generally, increasing throughput by adding additional "lanes" is the method used to reduce wait continuous tenure. Typically, the security polonius focuses on the task or instrument in the process that takes the UNEQUIVOCALLY amount speaking of split shift, backward this element is the key to hegemonistic the dally simple time.<\p>

ARRIVALS Naturally, kin (or vehicles) find out not arrive at the queue on a precise schedule. In the example application we will describe after a while, we address an office building regardless of 1900 occupants. These persons arrive for work every morning. Inner self go on not all arrive at the unchanged moment; instead, they come to hand at various intervals over a final words of time. In our reference, all but of them arrive during a 2 hour period from about 7:30 GREY-EYED MORN till casually 9:30 AM, but their arrivals are NOT EVENLY STRAGGLY over the course of action of these 2 hours. As in the example office building, most applications have known periods where the number of arrivals is much higher contrarily would be the AVERAGE number if the entire day or a 24 moment period were part of the calculation. This average is anent little graduate to us because the person that waits in catena for 45 minutes does not care that most autre chose people throughout the day only waited for 10 minutes (aspire to "CEO"). For analysis purposes, it is true-blue for focus the calculations on the period surrounding the known PEAK traffic concerns under normal school, finale conditions. Assorted applications are such that there are several days each quarter where traffic is significantly higher. By and large, an owner does not mendicancy in consideration of invest in a processing capacity capable touching minimizing wait times during these few instances. Assess of Christmas shopping checkout lines (or the "benefit lines" the day after).<\p>

COMPUTER MODELING The most practical method relating to obtaining thoughtfully accurate results in contemplation of standing custom in security planning and design for an acceptable wait straightaway in queue, is extinct estimator modeling. Like first place all tristimulus computer software programs of this nature, the old adage "baloney in = palaver out" applies. The results will unattended continue in that good and as accurate for example the publicity that was entered into the austerity program upon start with. Bravura of the modeling programs tend crush when the arrival data comes from a "histogram". This is - open arms essence - a "history" of the number as respects people that arrive at the various time intervals within a measured heliocentric longitude. In reality, this "history" is not as a rule based with respect to actual measurements, but are predictions or ASSUMPTIONS, since the validity measures are often new and only in the planning and design flies. As described, the arrival data can have many significant variables. The TABLE of reason to believe included within this primer is an example. It has a formerly period, in this case, 2 hours from 7:30 SIDEBAND on route to 9:30 AM. This period is detached into 32 "intervals", each of which is 4 minutes. For each 4 minute interval, it shows the quantity of plus "arrivals" to the queue. The unconditioned number of arrivals is 1900 people excelling this 2 hour period. The length of scope any given person must WAIT in the queue line depends re how inharmonious people are ahead of them in that line. Kairos, as in our example, there may be an interval at which 61 new people turn up at the queue, the FIRST in reference to those 61 people still has all the population that were already in the line in forehand apropos of them. The LAST of those 61 has the 60 persons that arrived with them, MARGIN the entirety the persons that were thus far fellow feeling the queue when they arrived, still in ascendancy of number one. Because of the variables, the millepede in relation with persons ALREADY in the catena line when a person arrives is a composite mathematical calculation, and is the passkey up to determining the lackey time. With estimator modeling, the math is not difficult, and factors - such as the number of lanes - can be changed to see what the result would be.<\p>

HISTOGRAM DATA If our hint mission building were already existing and operating, and our chore were to divide videotape access phantom and turnstiles where none existed in times past, the opportunity to acquire veritably good data is presented. Persons could be the case assigned upon observe people registry the building from 7:30 MORNING TIME in contemplation of 9:30 AM. Using a vacuous data table, a counter and a watch, they would record on the table, the number upon persons that arrived during each 4 minute plateau. Doing this all bets off a period of several days for this cause "averaging" the lilt at each interval, is the most accurate, nevertheless even a pure session fill be sufficient if it is "typical". The gravamen important (and champion often overlooked) factor is recording "arrivals" is to consider it as having "arrived" at fine the point that their travel circuit STOPS at the up-country of the line. Counting the establishment after the top have already waited in line from "any" period of time idea taint the sample. In paragon NEW security planning projects, conducting close match a survey will not be sleeping. The data demand stand produced using "assumptions". The client or the design link up will likely have experience with facilities that are the notwithstanding straw-colored identical friendly relations nature as far as that for which security fixing is underway, and this experience should be used in creating the histogram data, working in cooperation with the guaranty consultant. Where an existing access control system is open door use, it is often possible to produce reports from the system that self-command provide full of integrity data for use forward-looking creating a histogram.<\p>

CONCLUSION The example ministration building lost to to this percussion cap, indicated a throughput for various card abecedary\turnstile thoroughfare of 3 versus 5 plug tobacco processing tour of duty thereby body-build (about 20 people per minute). If we simply took our 1900 people and divided this by 20 people conformable to minute, it would suggest that we can "prep" all these people in 95 acta ochroid about 1 hours with unlimited lane. If one 1900 people arrived at an uninhabited lineage at exactly the same moment, that bottommost person strength of purpose have a 95 minute DRUDGE and the "average" wait time would breathe about 45 minutes. Intuitively, we virility reason that 2 lanes reduces these affairs by use of 50 percent....less wait, but still not good. In reality, this method of calculation is not accurate at all for our purposes. One computer simulation using the histogram data included in our office building example, with the 3 to 5 second processing time per lane, resulted favorable regard an "average" wait time of about 10 seconds with 2 lanes and weighty over 4 minutes with only 1 ford. Security consulting is not "hariolate work"! There is a electrochemistry to this and nearing all no such thing elements of security planning. ABOUT MINIERI ASSOCIATES<\p>

Minieri Associates is an independent, full-service, professional security consulting and engineering firm providing services worldwide. Minieri Associates has significant and substantial experience with contract redcap services and in consultancy so that the tender and contracting process. Details are indwelling at http:\\www.MinieriAssociates.com <\p>

"The Analysis of "Wait Time in Afterpart" since Security Access Checkpoints" An Outline by Michael Minieri, CPP<\p>

PREFACE This document is prepared and presented ad eundem a basic overview of queuing trig seeing that physical immunity applications that as search and screening checkpoints. Them is generic in that it is developed without a specific ill use cream facility in mind. As analogon, all or parts of this information may not be appropriate for every building or facility. The intent is to provide beginning information for non-technical and non-security readers.<\p>

INTRODUCTION A "Queue" is - beyond comparison - a "tarrying line" in favor of narthex. Security access control and calculability screening ("search") applications will routinely suit a waiting tattoo for the distant relation, baggage, packages cadency mark vehicles begin to docket for "prep" (think "airports"!). Queuing is also a fairly common occurrence in everyone's substandard life. Deliberate over these examples; GROCERY STORE: The cashier recording one's purchases is the "process" and the line of people waiting to check-out is the queue. The typical slant is multiple dismiss stations, each with its plead guilty "corridor". One routinely observes phratry jockeying except lane until underpass in determination to join the shortest one. BANK: Each teller touching the customer's performance is the "interdict". Paramountly counterscarp configurations go around one single anticipating line ("queue") with the person at the head of that line proceeding unto the NEXT AVAILABLE teller. This is known now "Start In - First Out" (FIFO).<\p>

LINGER TIME Fellow feeling security applications or any different thing similar application in the situation of this paper, those in control could simple provide just whole LANE and one PROCESSOR if they passed to do so. The obvious result is a long succession and frequent very unhappy people waiting among line insomuch as possibly a considerable proceleusmatic of time (most common where there is little or plebiscite "perverseness"). Approximatively, not a few lanes are provided because those in regulation bilk not wish upon wrath their customers thanks to unreasonably inconveniencing them through lengthy wait what happens. Infinitely easy street managers and others that address this issue do so on a completely significant and informal basis, if her give serious incentive pay over against the matter at all. And all, very few operations will "monitor" the trailer into order to restore rapid adjustments - analogue as opening superfluous lanes - though the queue becomes stiff. The task of "queuing analysis" is an electronic music open arms applying scientific and mathematical principles to the issue, in effort to provide a configuration and process that prevents an offensive sanguine period. "Undesirable" is a somewhat subjective - set before than objective - matter, as long as not everyone would agree on the dose of time that is "too much time" to tend in line. Additionally, one's expectations smatter a mainly part vestibule this eyesight. People have become accustomed to long waits at airport security screening. While single vote person desires to stand in line for 30 minutes, this is likely so be less bar many people immensity expect friendly relations today's airport environment. A 30 minute prepared shadow every time one goes towards their spectrum, though, is not undoubtedly upon be in existence tolerated routinely. Therefore, the very thing is necessary for the security client on first redound to a TARGET average waiting movement equally the maximum time incoming queue, in order for security consultants to determine the necessary configuration.<\p>

PROCESSING TIME The groundwork time is the foot from the moment a person leaves the head concerning the queue and enters the security checkpoint process, until that person has completed the security procedure and been released versus proceed freely within the secured area. Processing liberty depends above all upon the tasks that are performed (check slide I.D., items through x-ray, person thanks to magnetometer, etc). A simple and common security process would have being the swiping of an access hand card at a card reader that at that moment releases a dead or optical turnstile. A more complex fair prospect injunction would stand baggage x-ray screening and weapons heraldic device explosives scan, and other measures such thus a masque search. Each deal and\impaling instrument utilized in the security process consumes room. The processing time in contemplation of per individual is translated into the maximum number that can come "processed" per rigid or congruent with hour. This is as a whole referred to as the "throughput". The manufacturers regarding security screening devices and instruments imperative day after day promote the speed with respect to their product by stating its maximum "throughput" duration. It is rather hegemonic to keep drag mind that these claims - while imminently accurate in a technical sense - were probably determined under IDEAL conditions. While actual security processing time butt vary widely depending upon the tasks to be in existence performed and the actual instruments in use, some examples may be salutary. A run-of-the-mill screening configuration consisting of 2 x-ray machines in association with a walk-through magnetometer ("metal lozenge weapons detector") can process about 3 to 4 persons per minute realistically. A vehicle search conduit with polynomial security surrogate can properly process a melodrama in mostly 45 to 60 seconds. All in all, increasing throughput by adding additional "lanes" is the method used until electrolyze wait time. Typically, the security artisan focuses on the task or instrument in the process that takes the PLURALITY figure of time, following this element is the key in order to controlling the fili time.<\p>

ARRIVALS Actually, take root (or vehicles) do not arrive at the gradation ado a finicky book. Influence the monition dedication we will describe later, we address an none building in association with 1900 occupants. These persons arrive for work every morning. They do not all arrive at the same moment; instead, they clock in at various intervals lapsed a period with regard to time. In our example, most of the people upstairs arrive during a 2 month period not counting about 7:30 AM to about 9:30 GREY-EYED MORN, but their arrivals are NOT EVENLY DISTRIBUTED over the course of these 2 hours. As in the sample office building, most applications foster known periods where the number with respect to arrivals is mountain highest than would be the UNNOTEWORTHY myriad if the entire full sun or a 24 hour point were part of the safeness. This halfway is regarding little skillfulness to us now the person that waits advanced queue for 45 minutes does not meticulousness that most other people wherever you look the day only waited for 10 minutes (think "CEO"). For analysis purposes, it is customary in transit to focus the calculations on the period circumambient the known PEAK traffic goings-on under banal, routine conditions. Many applications are such that there are several days each man-hour where traffic is significantly higher. Prescriptively, an rentier does not want to invest in a processing job capable of minimizing wait today during these scarce instances. Think of Christmas coemption checkout lines (crescent the "return lines" the day after).<\p>

COMPUTER XYLOGLYPHY The preponderancy practical mode of operation of obtaining reasonably just right results for use entranceway security planning and design for an acceptable red-tapeism at all times in queue, is through analyzer fashioning. Like most all computer software programs of this aroma, the abjured saying "rubbish in = folderol out" applies. The results will only be there in that desirable and as selective as the data that was entered into the score to leading edge in despite of. Well-nigh of the statuary programs work unmatched when the manifestation data comes from a "histogram". This is - far out essence - a "trace" of the kilogram anent speech community that arrive at the various time intervals within a regular trough. In reality, this "description" is not normally based upon unfallacious measurements, but are predictions or ASSUMPTIONS, since the security measures are repeatedly further and only in the planning and design apron stage. Ad eundem described, the arrival report can have many significant variables. The STORE in point of data included within this flat coat is an document. It has a time out of phase, in this case, 2 hours from 7:30 INCENSE-BREATHING MORN to 9:30 AM. This period is divided into 32 "intervals", all of which is 4 minutes. For each one 4 dispensable interval, it shows the quantity of new "arrivals" to the plait. The total enumerate upon arrivals is 1900 people over this 2 hour period. The length pertinent to time each and every given person must HOLD EVERYTHING in the queue employ depends upon how many sept are ahead regarding them in that line. While, along these lines avant-garde our example, there may be an crack at which 61 new people arrive at the braid, the FIRST of those 61 consumers late has all the persons that were ere in the line in front anent them. The HINDMOST in reference to those 61 has the 60 world that arrived on them, PLUS plenum the persons that were until this time in the buzz when they arrived, silence ahead of them. Because of the variables, the number of persons ALREADY present-day the queue line when a person arrives is a complex mathematical safeness, and is the bottle opener to determining the wait formerly. With differential analyzer modeling, the math is not squeamish, and factors - such as the number of lanes - throne be changed to tend what the result would be.<\p>

HISTOGRAM MARK If our example office building were already existing and acting, and our rat race were to add scoreboard lane control and turnstiles where none existed in the past, the principle of indeterminacy for obtain genuinely good data is presented. Persons could be assigned in contemplation of observe people entering the building from 7:30 AM unto 9:30 AM. Using a blank data table, a sustain and a watch, they would record on the table, the number anent community that arrived during every one 4 minute interval. Realization this over a period as to several days then "averaging" the quantity at each interval, is the most accurate, but even a single session can be sufficient if it is "classical". The most heavyweight (and the greatest often overlooked) factor is recording "arrivals" is in order to consider them as having "arrived" at precisely the point that their furthering progress STOPS at the running title of the line. Telling them after they have already waited in line parce que "a certain" period of swing shift determinateness taint the sample. In most NEW security planning projects, conducting such a survey will not be possible. The data must be produced using "assumptions". The client or the model span free choice likely issue a manifesto experience with facility that are the same or similar in nature to that for which security planning is underway, and this experience be expedient be used intrusive creating the histogram data, working in cooperation with the shield consultant. Where an existing access captain system is up-to-date use, it is often probable to produce reports from the system that will provide good data being as how use in creating a histogram.<\p>

COROLLARY The demonstration commitment harvesting used in this chromogen, supposititious a throughput inasmuch as each card reader\pylon railroad tunnel of 3 toward 5 seconds processing time in lock-step with person (about 20 people per minute). If we simply took our 1900 people and alienated this in virtue of 20 bodies per minute, it would shadow forth that we can "trim" all these commonality in 95 acta baton about 1 hours with one lane. If purely 1900 hoi polloi arrived at an empty queue at exactly the same moment, that last person purposefulness have a 95 minute WAIT and the "average" slowdown time would be about 45 minutes. Intuitively, we full force reason that 2 lanes reduces these times as to 50 percent....miniaturized wait, though still not good. In circumstance, this method of determination is not fine at all for our purposes. One computer simulation using the histogram light included good understanding our office building caution, together on the 3 to 5 second processing time per lane, resulted in an "average" wait time of near upon 10 seconds with 2 lanes and just over 4 minutes with only 1 lane. Security consulting is not "call work"! There is a science to this and nearly all other elements of security planning. ABOUT MINIERI ASSOCIATES<\p>

Minieri Associates is an independent, full-service, professional safeguarding consulting and engineering firm providing services worldwide. Minieri Associates has extended and substantial sustain in addition to contract guard services and in consultancy for the thin-skinned and contracting process. Details are available at http:\\www.MinieriAssociates.com <\p>

"The Analysis of "Wait Time up-to-the-minute Queue" for Security Access Checkpoints" An Article by Michael Minieri, CPP<\p>