An Evaluation Of The Time Constrained And Resource Constrained . - CORE

1y ago
4.21 MB
185 Pages
Last View : 21d ago
Last Download : 6m ago
Upload by : Cade Thielen

Calhoun: The NPS Institutional ArchiveTheses and DissertationsThesis Collection1996An evaluation of the time constrained and resourceconstrained scheduling features of commerciallyavailable project management softwareNorwood, John Sheppard.Monterey, California. Naval Postgraduate School





ABSTRACTAnEvaluation of the Time Constrained and Resource ConstrainedScheduling Features of Commercially Available ProjectManagementSoftwarebyJohn Sheppard Norwood, M.S.E.The University of TexasSUPERVISOR:The majorat Austin, 1996CalinM. Popescusuppliers of commercially available projectmanagementsoftware were identified. These suppliers were surveyed to ascertain thenature of the time constrained and resource constrained schedulingeffectiveness provided by the software.features of the software as well as theThe surveyalso identifies themajorminimum and recommended computerhardware requirements for the software. The software suppliers wereallprovided with the same sample network for time constrained and resourceconstrained scheduling.Theto evaluate the effectivenessresultsof the scheduling calculations are analyzedof the software's procedures.Nospecificrecommendations or opinions are given concerning any of the individualsoftware products or

TABLE OF CONTENTSABSTRACTiiiTABLE OF CONTENTSivLIST OF TABLESviLIST OF 4BACKGROUND62.1Scheduling Methods2.2Time Constrained Resource Scheduling102.3 Resource Constrained Resource Scheduling136RESEARCH METHODOLOGY173.1Data Gathering173.2Methods of Analysis20PRESENTATION OF DATA234.1Baseline Solution4.2Time Constrained2325Solution294.3 Resource Constrained Solution4.45.34of ResponsesANALYSIS OF DATA.36Time Constrained Resource Scheduling Procedure365.2 Resource Constrained Resource Scheduling Procedure395.16.SummaryCONCLUSIONS AND sfor FutureResearchAPPENDICES5052A:Sample Survey53B:Bar Chart58C:Resource Histogram of Sample Project by Early StartofSample Project by Early Startiv60

D:Bar ChartofSample Network After Manual Time Constrained ResourceScheduling61E:Resource Histogram After Manual Time Constrained Resource Scheduling63F:Bar ChartofSample Network After Manual Resource Constrained64SchedulingG: Resource Histogram After Resource Constrained Scheduling66H: List of Vendors67I:SummaryofVendor Responses73BIBLIOGRAPHY78VITA80

LISTOF TABLESTable1:Results of Baseline CalculationsTable2:Results ofTable3:Results of Resource Constrained CalculationsTime Constrained CalculationsVI242833

LISTFigure1:Time Constrained Resource SchedulingPartFigure2:OF FIGURESIA(ProductsResultsthrough G)37Time Constrained Resource Scheduling ResultsPartIH through M)(Products38GFigure3:Resource Constrained Histogram for ProductFigure4:Resource Requirement Curves for Products JlFigure5:Resource Constrained Resource Scheduling ResultsPartFigure6:I(ProductsA-42J5through H)4446Resource Constrained Resource Scheduling ResultsPartII(ProductsIthroughVIIM)47

INTRODUCTION1.1.1PurposeIt isthe intention of this thesis to analyze the performance of the timeand resource constrained resource scheduling procedures of commerciallyavailable projectmanagement schedulingsoftware. There are currentlyavailable a multitude of software productstypes of project managers, not just thosewhich are intended for the use of allin theconstruction industry.these software products focus on only one of themanyMany ofaspects of a projectmanager's concerns.In general, projectmanagement software can beclassified into fourgeneral categories: accounting, communication, scheduling, and multifacetedsoftware products. The accounting type of software products are designed totrack cost and resource expenditures on each of the individual tasks whichmake upthe overall project.These products provide for the planning ofresource utilization and a detailed history of where resources have beenexpended. They also usually provide a comparison with a selected basetypically the project budget.of which tasks orline,This provides the project manager with a pictureactivities areexceeding the anticipated costs.Fromthis

information, project managers can focus their attention on the activities which,historically,have resultedA second generalin costover runs.category of project management software products,the communication or graphics type, are designed as a communication tool.These products allow the project manager to graphically represent the status ofeach task oractivity.With these graphic representations, the project managercan more easily communicate to superiors, subordinates, and colleagues, thestatusof eachactivity, pastperformance, and expected future outcomes.These software projects do not actually schedule theThey depend on information provided bysoftware product topercent complete,ons, orshowetc.either theactivitiesof a project.manager or anotherthe relationships between activities, scheduled dates,Assuch, these products are typically supplied as add-companion products to scheduling software products.Whatistypically called scheduling softwareisthe third generalcategory of project management software products. These products allow theprojectmanager to scheduleactivities withingiven constraints. The constraintscan be either external, such as required phase and contract completion dates, orinternal,such as one activitymaynot begin until another activityiscomplete.External constraints can be considered those restrictions placed on a projectfrom outside the project management organization or the projectitself.One

typicalexample of an external constraint would be a required delivery date orcontract completion date. Internal constraints are considered to be thoseimposed by the project manager for business reasons or as aprofessional judgment.Software products whichleastofExamples of these types of constraints are how manypeople to assign to a particular task, or the ordercombination of atresultfallinwhich to accomplishtasks.into the fourth general category provide atwo of the previousAsthree categories.such, theseproducts can be termed multifaceted project management software.Thedailyability toautomatically level out peaks and valleys in the requiredamounts of resourcesisone major feature of scheduling software, and themultifaceted products which incorporate scheduling software features. Thisprocedureistypically referred to as "leveling," "smoothing," or "timeconstrained resource scheduling."softwareisA second major feature of schedulingthe ability to schedule activities based on themaximumamounts of a given resource or resources. This procedureisresource "allocation," or "resource constrained scheduling."issue,resource constrained schedulingisavailablereferred to asTo confusethealso often referred to as "leveling."The procedures and computer algorithms whichare used to performthe time and resource constrained scheduling procedures can be very effective.However, these procedures haveseveraldraw backs.First,they are inherently

inflexibleand sequentialin nature.Secondly, they rely on the expertise of thecode writer and project manager to makeproductsmaylogical decisions.Givennot always provide the optimal solution. Projectthis,thesemanagementsoftware products compensate for these shortcomings with the rapid resultsprovided by the speed of modern desktop computers.the limitations of scheduling softwarearticle series forPMNETwork (LevineisA gooddiscussion ofprovided by Mr. Levinein histwo1994a and 1994b).This thesis will evaluate the effectiveness of the time and resourceconstrained resource scheduling procedures of various scheduling softwareproducts by comparing their results with a manually calculated optimalsolution.26The optimalactivitiessolutions are developedfrom a short sample network ofwith one resource, mandays, assigned to eachactivity.Thenetwork was designed to be simple enough for manual calculation of time andresource constrained resource scheduling and yet large enough to demonstratethe differences between software products.1.2ScopeIn order to accomplishitspurpose, this thesisfirstidentified asmanycommercially available computer scheduling software products as possible.

The vendors of these products were then askedto respond to a short surveythe characteristics and requirements of their product.onIn addition, the surveyrespondents were asked to enter the sample network of tasks into theirproduct.The respondents werealso asked to perform a time constrainedresource scheduling calculation on the sample network as well as a resourceconstrained resource calculation.groupedintotwo separate samplewere then comparedThe variouspopulations.resultsof the calculations wereThese sample populationsto the optimal solutions calculated manually.

BACKGROUND2.Scheduling Methods2.1It isnot the purpose of this thesis to discuss at any length the variousscheduling methods.mostIt iscommon methodsconsidered necessary, however, to briefly review theand terminology.Anexcellent reference for acomprehensive discussion of scheduling methods and proceduresal.isModeret(1983).The mostprojectisbasicmethod of scheduling the variousbar charting. ThisGantt chartishorizontal barisalsocommonlyactivitiesof any givenreferred to as a Gantt chart.a graphic representation of the duration of each activity.isplaced for each activityin the overall projectsuch thatAAitswidth represents the activity's overall duration. The relative placement of thebars right orleftindicates the anticipated start and finish dates.draw back with Ganttdependencies betweenchartsisthat theyactivities.used as a simple graphical toolinTheprincipaldo not depict the relationships andIn spite of this, Gantt charts arecommunicating projectstatus.commonlyAlmostallscheduling software programs include Gantt charts as a basic form of discussedlater,Appendices B, D, and F are typicalbar, orGantt

The next most common method of project schedulingthe Critical Pathsubcategories.CPM can actually be dividedMethod (CPM).Thefirstisreferred to asintotwo majorbeing activity on arrow, or simply the arrowADM each activitydiagramming method (ADM). Witharrow. The duration of each activityisisrepresented by ancentered just beneath the arrow.Activity arrows are connected at nodes which represent the dependencies orrelationshipsbetweendiagramming method (PDM)exact opposite ofeach s.on node or the precedencethe second sub-category.isPDM,Ininformation relevant to the scheduling of an activity.betweenactivitiesisin thatThedepicted with arrows which lead fromCPM methods solve the basicthey accurately represent the relationshipsactivities.Theprincipal advantageof CPM techniquesscheduling calculations which arebackwardpasses.from theactivitiesalmost therepresented by a node, typically in the form of a box whichproblem with bar chartsactivityisADM in the way that activities are represented.predecessors to successors. Both of thesebetweenPDMcommonlyThe forward passfinishof precedingisthe ability to perform thereferred to as forward andcalculation develops the early start of eachactivities.which have no predecessors. TheThe process begins with anyearliest possible startof any

successor activitiesiscalculated from the latest finish of allplus any lag or additional delay required.itspredecessorsConversely, on the backward pass,the late finish and consequently the late start of each activity can be calculatedby starting from theactivitiesactivitieswith no successorswith no successors. Theislate finishtypically set at either the early finishThelatest activity,or the required completion date.predecessorthen determined from the earliest late start of allisminus any lag or requiredamount of total anddefined as thedelay.isfree float for each activity.amount of time which antheactivityamount of time which theThecommonlythese scheduling methods.of theof anyitssuccessorsalso provide theactivity's free floatiscan be delayed with outactivitydelaying the early finish of the entire project.least total float islate finishThe backward pass candelaying the early start of any succeeding activityof allTheSimilarly, the total floatofcan be delayed withoutseriesof activities with thereferred to as the critical path, hence thenameforCPM in either or both of its forms is the basis forthe vast majority of currently available scheduling software.A thirdscheduling method calledand Review nce Evaluationprincipal featureof PERTthe incorporation of multiple possible durations and the associatedprobability of each duration with eitherarrow or precedence diagramming.

UsingPERTa project's total duration can be calculated as well as theprobability of actually meeting the projected date.PERThas proved usefulresearch and development projects as well as other areas involvinguntried technology and techniques.PERTTheapplicabilitynewinorand effectiveness ofinversely related to the degree of certainty in the duration of theisactivitieswhich compose aproject.Onefinalnote onPERTisthat thetermisoften used incorrectly to describe the precedence diagramming method.In researching this thesis awide variety of new scheduling techniqueswere encountered. Several of these techniques deserve mention. Russell andWong(1993) and Russell and Caselton (1988) describe a scheduling methodand software product developed for projects which involve a significantrepetitionstiffnessof ainof activities. Moselhi (1993) describesmethod of structuralThis techniqueanalysisseriesisof time-the directanalysis can be applied to scheduling projects.applicable to projects with scheduling constraints, and thecost trade-offs. Badiru (1993) presents a variation onwhich resources replaceschedule.howactivities as the principal buildingblock of aCPM

2.2Time Constrained Resource SchedulingTime constrained resource schedulingisone of the two basic resourcescheduling procedures performed by the majority of scheduling software.Unfortunately, the majority of research and papers have been devoted toresource constrained resource scheduling, the other basic resource schedulingprocedure (Seibert and Evans 1991). Resource constrained resourcescheduling will be discussedTheinthe next section.starting point for time constrained resource scheduling is aCPMnetwork of a project for which the forward and backward passes have beencompleted. Each activityisthen assigneditsrequired resources based onunlimited availability of the required ycan then beavailable free and total float in order to minimize therequired resource levels between time periods.The processiscarried out for each non-critical activity in the project for the simple reasonthat the critical activitiescritical activitywouldhave nofloat.Any changeeither violate the relationshipsdelay the early finish of the project.there are no set limits on theinthe scheduling of abetween theactivities orIn time constrained resource schedulingamount of resources10available.The only hard

criteria is that the fixedcompletion of thementioned1finishin section 2.last activitynot be delayed.Asabove, the fixed completion can be either the earlyof the overall project as calculated by the forward pass, or an imposeddate such as the required project completion.schedulingisTime constrained resourceconsidered necessary as fluctuationsinresource levels "are veryundesirable because they often present labor, utilization, and financialdifficulties to the contractor."(Easa 1989)The methods of time constrained resource scheduling cangenerally becategorized as either heuristic or optimization. The heuristic approach uses theapplication of various rules of precedence to decide which of several activitieswillbe scheduledchangeinfirstwillbe postponed when an undesirableresource requirements occurs.other hand examinesbest solution basedTheallAnoptimization approach on thepossible scheduling scenarios and then chooses theon a given measure ormetric.principle advantage to a heuristic approachcalculation timeisrequired.optimization approachevaluated.and whichisthat significantly lessConversely, the principle disadvantage of anthat each possible scheduling scenarioThe number of calculations required andapproach typicallyislimits its applicability to11must bethe associated time for thisdesktop computers, even for short

simple networks. For this reason, the majority of scheduling software productsutilize a heuristicTheapproach to time constrained resource scheduling.principle disadvantage to a heuristicapproach can best bedescribed as the approximate nature of the result.A heuristic method,very nature will not necessarily find the one best solution. Rather,itbyitsuses theapplication of various rules to decide which activities should be scheduled andwhich should be postponed. The choice of prioritiesOncan significantly affect the outcome.inscheduling activitiesthe other hand, the optimizationapproach can choose which scenario provides the "best" solution by evaluatingeach and every scheduling scenario.There are twocommonmetrics used for evaluating the effectiveness oftime constrained resource scheduling procedures. Theof the absolute values of the changesperiods.The second metric beinginthefirstmetricisthesumresource requirements between timesum of the squares of the changesinresource requirements per time period. Either metric provides a measure ofthe effectiveness of the procedure at reducing the variation in resourcerequirements per time period for a particular project or network.Itmust bepointed out that neither metric can be used to compare time constrainedresource scheduling results between projects. The metrics are only usefulcomparing theresultsof a scheduling procedure with the original12CPMin

network orbaseline.The uniquecharacteristics of each individualnetworksuch as number of activities, amount of float, and percentage of criticalactivitiesprecludes comparisons between networks. The squaring metric doesprovide an advantagein theexaggeration of small differencesintimeconstrained resource scheduling performance. For this reason, the squaringmetricwas chosenin evaluating the effectivenessresource scheduling procedures used2.3of the time constrainedin this thesis.Resource Constrained Resource SchedulingThe secondbasic resource scheduling procedure,by scheduling software,isknown bya variety of terms.whichisconductedThe most commonlyused terms are resource allocation, resource constrained scheduling (Drexl andGruenewald 1993) and (Oguz and Bala 1994), and unfortunately, resourceleveling (Primavera 1991).As withthe procedure for time constrainedresource scheduling discussed above, resource constrained resource schedulingbegins with a resource loadedCPM diagram with the relevant calculations ofearly and late, start and finish, and free and total float completed.constrained resource scheduling the early finish of theor locked.Rather thetotallast activity isamount of a resource or resources13For resourcenot fixedavailableis

given a setmaximum amountavailable per time period.terminology, resource constrained resource scheduling.available limit of a resourceinsomemay becases, variable with time.actual resource availability orare set the projectispostponeduntil thetheThe maximumconstant over the duration of a project, orThelimitsmanagementimposed may be theOncedecisions.rescheduled one activityinsufficient available resources toHenceata time.resultofthe resource limitsWhen thereaccomplish a given activityitaremust beresources are available. There are two basic variations onthese rules which should be considered.Thefirstallows for an activities totalduration to be adjusted without changing the total required resources tocomplete thescheduling.activity.ThisiscommonlyThe name derives fromreferred to as effort driventhe fact that the anticipated effort andavailable resources determines an activities duration.The secondto allow activities to be temporarily suspended or interrupted toresource requirementsin other,morereferred to as splitting an activity.optionwhen performingcritical ysoftware products allowsplits asanscheduling.Resource constrained resource scheduling methods can also beclassified into thesame two general categories of heuristic and optimizationmethods discussedfor time constrained resource scheduling.14Theheuristic

method followspreset rules and priorities to determine the order inactivities are rescheduled.The optimization method examinesallwhichpossiblescheduling scenarios and then chooses the best solution.Similar advantages and disadvantages apply for resource constrainedresource scheduling as do for time constrained resource scheduling.Optimizationiscalculation andmemoryoffers only an approximate solution.description of justhowintensive while the heuristic approachOguz and Bala (1994) providecalculation intensive the optimizationmajority of scheduling software uses the heuristicamethodmethod duegoodis.Theto the limitationsof desktop computers.Onepoint which must be stressed for the heuristicconstrained resource schedulingismethod of resourcethat the order, or priority, into schedule a non-critical and resource intensive activity aheadmayForsignificantly delay the early finisheither the heuristic or optimizationof theactivitiesFor example, the electionare rescheduled can significantly affect the outcome.activitywhichof acriticallast activity.method of resource constrainedresource scheduling the typical metric of performanceisthe overall delay in thecompletion of the project as compared to the unconstrained early completion.A shorter schedulingrelatively high dailydelay being preferred over a longer one due to theoverhead costs associated with most projects. The analysis15

in this thesisuses the metric of the overall delayinthe project expressed as apercentage of the original duration. The one drawback tothat the results can not becompared between twoeven true when the overall delaythe original duration.inThe reasonscompletionfor this lackisthismetricis,different networks.again,Thisisexpressed as a percentage ofof comparability are the sameas for time constrained resource scheduling.ThemoreThisliteratureplentifulison resource constrained resource schedulingismuchand varied than that for time constrained resource scheduling.probably a direct result of themuch more troublesome problem of nothaving enough resources as compared to the somewhatminimizing variationsinresource requirements.Moderidealisticetal.problem of(1983) providean excellent and thorough discussion of the theory and methodology ofresource constrained resource scheduling.Shanmuganayagam (1989), andDrexl and Gruenewald (1993) provide some innovative approaches to themathematical aspects of resource constrained resource scheduling usingoptimization methods. Finally, Russell and Caselton (1988) discuss theapplication of resource constrained resource scheduling to projects with ahighly repetitive series of activities.16

3.3.1RESEARCH METHODOLOGYData GatheringThe process of gathering dataphases.Thefirstfor this thesis involved four steps orbeing the identification of assoftware as possible.A literatureconstruction software resultedinmany vendors of schedulingsearch of previous surveys and reviews offour excellent sources of information. Badiruand Whitehouse (1989), Constructor (1992), and1994b)allThese fourprovided extensive and comprehensivelistswere consolidatedinto a databasePMNETwork (1994a andlistsof software vendors.of potential contacts. Thosesoftware products which were clearly not within the scope of this thesis wereexcluded. Duplicate vendor addresses or points of contact were retained asseparate records in the database to ensure that every vendor could becontacted.A survey of the basic requirements and features of typical schedulingsoftware was developed next. The survey covered the basic categoriesof:vendor information, operating system requirements, software features,software output, time analysis, resource characteristics, and resource analysis.In addition, the survey included a simple 26 activitysingle resource,network loaded with amandays. All of the relationships between the17activities are

finish to start.forThis network was intentionally kept relatively simple to allowmanual time and resource constrained resource scheduling and to increasethe chances of vendors actually responding to the survey.Anessential partsample network intoof the surveyisthe request that each vendor load thetheir software product.Each vendorisasked to provide abaseline tabular report of the network and a resource histogram,Theif possible.baseline reports as well as any other information provided are to be usedas a control to ensure that thenetwork was enteredinto the software correctly.After completing the baseline reports, the vendors are asked to performseparate time constrained and resource constrained resource schedulingcalculationsison the baseline network. For the time constrainedemphasizedthat the early finishof theavailability is set at tenslightlymenmaximumper day. This limitwasdaily resourceintentionally set justbelow the peak baseline requirement of twelve men per day.the surveyisattached as Appendix detail later inOnceSectionthe surveyTheitcan not be delayed. Forlast activitythe resource constrained calculations the totalcalculations,A copy ofindividual results will be discussed5.was developed eachtelephone to request their participationpotentialin the survey.18vendor was contacted byTheoriginal database

included over one hundred andfiftymany beingvendors,duplicate vendornames with various addresses, phone numbers and points of contact.Dueto the rapid rate of change in the software industrywere unableAlmostto be contacted.universally, either themany vendorsphone number wasdisconnected, had been changed, or the point of contact no longerthe company.Inone particularlawyers answered wasIn total, seventyin receivershipforand theirone vendors were able to bethis point in the research, duplicatemultiple vendors of theOf thecase, theworkedvendor addresses andsame software product wereeliminated.vendors contacted, twenty one were no longerselling ascheduling product or the product did not perform resource analysis. Only onevendor declined to participatefiftyinthe survey over the telephone.The remainingvendors were considered valid for the purpose of the survey andthesis.Each vendor wassent acopy of the survey with a coveraddressed to the point of contact. The covertheir participationletterthisletterrepeated the request forand detailed the scope and purpose of thisthesis.A list ofthe valid vendors with their mailing addresses, points of contact, telephone andfacsimilenumbersisattached as Appendix H.The next phasein thedata gathering processvendors to respond to the survey. Although19allwasto encourage theof the vendors were very

helpful over the phone, theywereless than enthusiastic in replying to theDuring follow-up telephonesurvey.callsproducts originally considered valid wereitbecame apparentin factthatsome of theaccounting or graphics typeSeveral vendors eventually declined to participate based on a lack ofsoftware.time to respond. This reduced the sample population to a total of thirty one.Eventually only fourteen vendors responded to the survey.3.2Methods of AnalysisTheanalysisof the data provided by the survey respondents wasstraight forward, but timeconsuming. The vendors responses to thefirsthalfof the survey were entered into a database for reference purposes. Thisdatabaseisattached as AppendixThe vendor's responsesanalyzed indetail.All the second half of the surveyof the datawere eachsets (unconstrained baseline, timeconstrained calculations, and resource constrained calculations) provided bythe vendors were analyzed.The unconstrainedbaseline providedwasevaluated as a control to ensure that the sample project had been enteredproperlyIn addition, the time constrained20and resource constrained

calculationswerealso analyzed to ensure that thenetwork logic was notviolated during scheduling.For the time constrainedwascalculations, the daily resource requirementextracted from either the tabular reports, Gantt charts, or the resourcehistogram provided. The daily resource requirement for each response wasentered into a computer spreadsheet.calculate thesum of theThe spreadsheet was then usedtosquares of the difference in required resources fromone day to the next for each respondent. The resultant was used as a metric ofthe effectiveness of the calculation procedures andcomputer algorithms of thesoftware product.For the resource constrainedduration of fifty one dayscalculations, the unconstrained baselinewas subtracted fromthe total duration of the projectafter running the resource constrained resource scheduling.Thedifferencewasdivided by the baseline duration of fifty one and multiplied by one hundred.Theresultantwas an expression of the percent delay caused bythe resourceconstrained calculation algorithms of each software product.The vendor responsesfor the time constrained and resource

Calhoun: The NPS Institutional Archive Theses and Dissertations Thesis Collection 1996 An evaluation of the time constrained and resource constrained scheduling features of commercially

Related Documents:

May 02, 2018 · D. Program Evaluation ͟The organization has provided a description of the framework for how each program will be evaluated. The framework should include all the elements below: ͟The evaluation methods are cost-effective for the organization ͟Quantitative and qualitative data is being collected (at Basics tier, data collection must have begun)

Silat is a combative art of self-defense and survival rooted from Matay archipelago. It was traced at thé early of Langkasuka Kingdom (2nd century CE) till thé reign of Melaka (Malaysia) Sultanate era (13th century). Silat has now evolved to become part of social culture and tradition with thé appearance of a fine physical and spiritual .

On an exceptional basis, Member States may request UNESCO to provide thé candidates with access to thé platform so they can complète thé form by themselves. Thèse requests must be addressed to esd rize unesco. or by 15 A ril 2021 UNESCO will provide thé nomineewith accessto thé platform via their émail address.

̶The leading indicator of employee engagement is based on the quality of the relationship between employee and supervisor Empower your managers! ̶Help them understand the impact on the organization ̶Share important changes, plan options, tasks, and deadlines ̶Provide key messages and talking points ̶Prepare them to answer employee questions

Dr. Sunita Bharatwal** Dr. Pawan Garga*** Abstract Customer satisfaction is derived from thè functionalities and values, a product or Service can provide. The current study aims to segregate thè dimensions of ordine Service quality and gather insights on its impact on web shopping. The trends of purchases have

Chính Văn.- Còn đức Thế tôn thì tuệ giác cực kỳ trong sạch 8: hiện hành bất nhị 9, đạt đến vô tướng 10, đứng vào chỗ đứng của các đức Thế tôn 11, thể hiện tính bình đẳng của các Ngài, đến chỗ không còn chướng ngại 12, giáo pháp không thể khuynh đảo, tâm thức không bị cản trở, cái được

Le genou de Lucy. Odile Jacob. 1999. Coppens Y. Pré-textes. L’homme préhistorique en morceaux. Eds Odile Jacob. 2011. Costentin J., Delaveau P. Café, thé, chocolat, les bons effets sur le cerveau et pour le corps. Editions Odile Jacob. 2010. Crawford M., Marsh D. The driving force : food in human evolution and the future.

Le genou de Lucy. Odile Jacob. 1999. Coppens Y. Pré-textes. L’homme préhistorique en morceaux. Eds Odile Jacob. 2011. Costentin J., Delaveau P. Café, thé, chocolat, les bons effets sur le cerveau et pour le corps. Editions Odile Jacob. 2010. 3 Crawford M., Marsh D. The driving force : food in human evolution and the future.