Dmci Homes Application of Pert Essays

Dmci Homes Application of Pert Essays Dmci Homes Application of Pert Essay Dmci Homes Application of Pert Essay information on units and important areas within the vicinity. Assistance on transactions concerning the developer, including following up documents * Community events  such as sports fests, family day, Halloween treats, Christmas party, etc. You are also able to enjoy the perks of living in a DMCI Homes community. Modern-day facilities that are standard features in the developments and which contribute to a more convenient lifestyle include: * 24-hour security service * Gated entrance and perimeter fence * Overhead water tank, deep well, and underground cistern * Covered bridge way connecting the residential building to the car park * Individual drying area at the roof deck Provision for CATV and telephone lines QUALITY WORKMANSHIP Expect efficient floor plans and high-quality structures with first-rate construction techniques in the development of all DMCI Homes projects, owing to its mother company DMCI’s 50-year c ommendable track record in the construction industry. DMCI Homes also provides one (1) year quality warranty that covers repairs, free of charge, on any workmanship defects of the unit. Fast and reliable, the companys construction of the residential buildings and turnover of units are within 6 to 12 months only. READY FOR OCCUPANCY AND MOVE-IN POLICY For as low as 20% down payment for mid-rise or 30% down payment for high-rise, a homebuyer may immediately move into his or her unit and enjoy the privileges of living in a DMCI Homes residential community, provided his or her unit is completed. Without the long wait, take pleasure in a resort living ambience right within your own backyard, or realize your condo unit’s earning potential sooner than you expected. II. Literature Review A BRIEF HISTORY OF SCHEDULING BACK TO THE FUTURE Presented at 4 6 April 2006 Hyatt, Canberra. Patrick Weaver FAICD, FCIOB, PMP. Director, Mosaic Project Services Pty Ltd Introduction The science of ‘scheduling’ as defined by Critical Path Analysis (CPA) will celebrate its 50th Anniversary in 2007. In 1956/57 Kelly and Walker started developing the algorithms that became the ‘Activity-on-Arrow’ or ADM scheduling methodology for DuPont. The program they developed was trialed on plant shutdowns in 1957 and their first paper on critical path scheduling was published in March 1959. The PERT system was developed at around the same time but lagged CPM by 6 to 12 months (although the term ‘critical path’ was invented by the PERT team). Later the Precedence (PDM) methodology was developed by Dr. John Fondahl in 1977 as a ‘noncomputer’ alternative to CPM. Arguably, the evolution of modern project management is a direct consequence of the need to make effective use of the data generated by the schedulers in an attempt to manage and control the critical path1. The evolution of scheduling closely tracked the development of computers. The initial systems were complex mainframe behemoths, typically taking a new scheduler many months to learn to use. These systems migrated to the ‘mini computers’ of the 1970s and 80s but remained expensive, encouraging the widespread use of manual scheduling techniques, with only the larger (or more sophisticated) organizations being able to afford a central scheduling office and the supporting computer systems. The advent of the ‘micro computer’ (ie, personal computer, or PC) changed scheduling forever. The evolution of PC based scheduling move project controls from an environment where a skilled cadre of schedulers operating expensive systems made sure the scheduling was ‘right’ (and the organization ‘owned’ the data) to a ituation where anyone could learn to drive a scheduling software package, schedules became ‘islands of data’ sitting on peoples’ desktops and the overall quality of scheduling plummeted. Current trends back to ‘Enterprise’ systems supported by PMOs seem to be redressing the balanceand offerin g the best of both worlds. From the technology perspective, information is managed centrally, but is easily available on anyone’s desktop via web enabled and networked systems. From the skills perspective PMOs are re-developing career paths for schedulers and supporting the development of scheduling standards within organizations. This paper tracks the development of scheduling (with a particular focus on Micro Planner and Primavera) and looks at the way the evolving technology has changed the way projects are scheduled and managed. In the Beginning Pre 1956 The concept of ‘scheduling’ is not new; Sun Tzu wrote about scheduling and strategy 5000 years ago from a military perspective, the pyramids are over 3000 years old, transcontinental railways have been being built for some 200 years, etc. None of these activities could have been accomplished without some form of schedule; ie, the understanding of activities and sequencing. However, whilst the managers, priests and military leaders controlling the organizations responsible for accomplishing the ‘works’ must have an appreciation of ‘scheduling’ (or at least the successful ones would have) there is little evidence of any formal processes until the 20th Centenary. Henry L. Gantt, an American engineer and social scientist is credited with the developed the bar chart (Gantt Chart) in 1917 as a production control tool. In its pure form, the bar chart correlates activities and time in a graphical display allowing the timing of work to be determined but not interdependencies. Sequencing is inferred rather then shown and as a ‘hand drawn’ diagram, the early charts were a static representation of the schedule. Fig. 1 A typical Gantt chart. Milestone charts were also in regular use by the 1950s2. Major contracts were subdivided into sections with target dates set for accomplishing the work required to achieve each ‘milestone’. However, as with Gantt Charts, all of the dates and durations shown in these charts were based on heuristics (rules of thumb) and/or experience. It was possible to identify slippage but any assessment of the impact of a delay was based on a personal view of the data rather than analysis. As a consequence when schedule slippage became apparent on major contracts, the tendency was to flood the work with labor and ‘buy time’ frequently at a very high premium. Independent of the development of schedule control processes based on bar charts and milestones, work on linear programming had been going on for a number of years. This branch of mathematics looked at the cause and effect of actions on each other in situations such as the flow of traffic along a freeway. One of the mathematicians involved in this work was James E. Kelley. CPM and Kelly and Walker3 The origin of CPM can be traced back to mid 1956. E. I. du Pont de Numours (Du Pont) was looking for useful things to do with its ‘UNIVAC1’ computer (this was one of the very first computers installed in a commercial business anywhere and only the third UNIVAC machine built). Fig. 2 – An early UNIVAC Computer Du Pont’s management felt that ‘planning, estimating and scheduling’ seemed like a good use of the computer! Morgan Walker was given the job of discovering if a computer could be programmed to help. Others had started studying the problem, including other researchers within Du Pont but no one had achieved a commercially viable outcome. In the period from late 1956 through to April 1957, Walker assisted by Kelly and others had scoped a viable project. Their challenge was to solve the time-cost conundrum. They could demonstrate that in preference to flooding a project with labor to recover lost time, focusing effort on the ‘right’ tasks can reduce time without significantly increasing cost. The problem was identifying the ‘right’ tasks! Fig. 3 – The Time / Cost Curve On the 7th May 1957, a meeting in Newark Delaware committed US$226,400 to a project to develop CPM; Du Pont’s share was $167,700, Remington Rand Univac contributed $58,700. Univac had decided to help ‘to keep IBM at bay’; competition can be useful†¦Ã¢â‚¬ ¦ but more important than the money was the people brought to the project by Univac. The Du Pont team was lead by Morgan R. Walker, key players from Univac were James E. Kelley and John Mauchly. Kelley was the mathematician and computer expert nominated by Mauchly to ‘solve the problem’ for Walker. The solution adopted by Kelley borrowed from ‘linear programming’ and used the i-j notation to describe the relationship between activities. This constrained the sequencing and made the calculations feasible (remembering the challenge was still to resolve the ‘time-cost’ trade off). This solution created a couple of significant challenges. One was gathering the data needed toload the computer model. Engineers were not used to describing work in terms of activities (tasks) with resource requirements and different costs depending on the resources deployed for a ‘normal’ duration and a ‘crashed’ duration. Gathering the data for the first CPM model took Walker over three months. The other problem was that unless you were a mathematician the concept of i-j was virtually meaningless! The ‘Activity-on-Arrow’ diagram was developed to explain the mathematics to management. Despite all of the problems, by 24th July 1957 the first analysis of the George Fischer Works schedule had been completed and the concept proven. The schedule included 61 activities, 8 timing restraints and 16 dummies. Fig. 4 A section of the George Fisher Works CPM schedule The major challenge then became reducing the number of calculations and variables to a level that could be processed in a reasonable timeframe. The estimate of the time needed to update a schedule of 150 to 300 arrows was some 350 hours of computer time per month. Some of the challenges were as basic as accessing the right computer; magnetic tapes storing the schedule data were prepared on the DuPont computers and then flown across the USA to be run on machines capable of analyzing the data. Development continued through 1958 and in March 1959 Kelley and Walker jointly presented CPM to the public at large at the Eastern Joint Computer Conference in a paper entitled ‘Critical Path Planning and Scheduling’. As with many innovations though, CPM nearly died as a concept. CPM saved DuPont 25% on their shutdowns, but they dropped the system shortly after the management team responsible for its development changed in 1959. Similarly, RemRand could see little future in the system and abandoned it! CPM as a technique was ‘saved’ by Mauchly ; Associates (including John Mauchly and Jim Kelley). Starting in 1959, they commercialized CPM, simplified the process to focus on schedule (rather than cost), organized training courses and developed an entire new way of ‘doing business’. CPM was popular but expensive – solving scheduling problems (eg loops) could cost the price of a small car! PERT and Other Systems PERT was developed independently by the US Navy Special Projects Office, Bureau of Ordnance (SP). A team comprising members of SP and consulting firm Booz, Allen and Hamilton was established in 1957 and produced its first report in July, 1958. Apart from introducing uncertainty into schedule durations, the lasting contribution the PERT teams have made to the business of scheduling was the invention of the ‘critical path’. Kelly and Walker used the name ‘main chain’ for the longest path through their schedule. By 1961, a multitude of PERT like systems had been developed including MAPS, SCANS, TOPS,PEP, TRACE, LESS and PAR. These systems were all network based and had distinguishing features of their own. PEP is particularly interesting as it was essentially ‘a connected bar chart; ie, a set of bars with links connecting the ends of related bars’5. A concept that has re-surfaced in a range of computerized scheduling tools in recent years. By 1968 PERT and CPM had emerged as the standard nomenclatures and dominant systems. Precedence Diagramming Method In 1961 John Fondahl published a report entitled ‘A Non-computer Approach to Critical Path Methods for the Construction Industry’6. This paper described the PDM system of scheduling and was offered as effective manual process to bypass the expensive computer based CPM system. The irony being PDM is now used by every computer based scheduling system, PERT has dies out completely and CPM is rarely seen and is generally only found in academic papers where the calculations are performed manually! Mainframe days†¦Ã¢â‚¬ ¦ Through to the early 1980s, to create a project schedule you either used a mini or mainframe computer system. Or drew and calculated schedules manually. Or did both; manual calculations first (to sort out problems) then pload the corrected and checked schedule to the computer. The run-time on the computer cost too much for errors! Schedulers were trained through a process of apprenticeships and mentoring; it cost too much and took too long to fix problems caused by inexperience! The consequence was the evolution of a group of project schedulers skilled in both the art and science of scheduling. H owever, as Kelley noted from the very earliest CPM training courses, there was a significant variability in the outcome for scheduling exercises caused by differing skill levels and perceptions on the trainees. The existence of scheduling departments meant the scheduling processes were standardized and the schedule data was largely ‘owned’ by the organization. Additionally, the desire of professional schedulers to exchange information and develop their skills would appear to have been the foundation for the evolution of ‘modern project management. PC systems Micro Planner Micro computers emerged in the late 1970s, machines like the Commodore and Atari were initially aimed at the enthusiast. However, by the end of the 1970s micro computers were starting to make their presence felt in the business world. One of the leaders in the business market was Apple Computer with its first ‘commercial’ PC, the Apple II being launched in 1979. The first commercial scheduling software for this class of computer was developed by Micro Planning Services in the UK. Running on the Apple II Micro Planner v1. 0 was released in 1980 after 14 months development, based on the ICL PERT mainframe system. The first IBM PC was launched in 1981; although the definitive IBM XT was not launched until 1983. In 1982, ‘The Planner’ is released for the 256K IBM PC and the Sirius/Victor. Windows’ type operating systems became available in 1984 (Apple Macintosh) with Microsoft’s ‘Windows v1. 0’ being launched in November ‘85. Micro Planner maintained their association with the Apple system launching graphical scheduling systems for the Apple Macintosh in 1986 and Windows in 1988; followed by the first true GUIb scheduling tool Micro Planner X-Pert in 1989. The author managed the Australian arm of the Micro Planner group from 1986 through to 1998 over this period the total annual sales of the business grew to more than $1 million. Primavera Primavera was founded in May 1983 by: Dick Faris, Joel Koppelman and Les Seskin (who owned a batch entry mainframe scheduling system). Today Primavera is arguably the dominant ‘high end’ project scheduling tool worldwide. But where did the name come from? Focusing on the then ‘mainstream’ DOS operating system, Primavera shot to prominence with the release of a 10,000 activity capable system in the late 1980s and has maintained its position as ‘market leader’ with a steady flow of innovative developments. The Changing Industry During the 1970s, the arrival of powerful project scheduling systems running on ‘Mini Computers’ caused the first major change. The lower operating cost of systems such as MAPPS on Wang and Artemis on HP and DEC hardware caused the rapid demise of mainframe scheduling systems. Apart from a few legacy systems the era of the mainframe was over by the mid 1980s. The ‘mini systems’ retained many of the characteristics of the mainframes though and required skilled schedulers to make efficient use of them. From the perspective of the people working as schedulers all that changed was the hardware and maybe the software vendor. The rapid spread of relatively cheap, easy-to-use’ PCs in the latter half of the 1980s spawned dozens (if not hundreds) of PC based scheduling systems including TimeLine and CA Super project at the ‘low end’, and Open Plan and Primavera at the ‘high end’ of PC capability. The ‘low end’ tools spread the availability of scheduling systems to a very wide audience and allowed everyone access to cheap computer based scheduling. This had two impacts, by the early 1990s no one was doing manual scheduling (apart maybe from a few ‘old timers’) and the number of people creating schedules on a part time, untrained basis exploded. At the same time, the increasing capability of the ‘high end’ systems annihilated the significantly more expensive mini systems. Scheduling had become a desk top PC based process. The last of the significant changes in the industry started in latter part of the 1980s and has continued through to the present time. Despite the ever increasing number of people using PC based scheduling tools; the competition in the market has driven prices down and caused a major consolidation of the industry. For many years, Microsoft Project could be bought for less than $100 per set. This decimated the ‘low end’ market. Similarly the cost of developing GUI interfaces and staying competitive in the features arms race at the ‘high end’ caused most of the system developers to move to greener pastures or simply close up shop. It is only since the start of the 21st century has this trend begun to change. The increase in the sophistication of Microsoft Project and the rise in its base cost to around $1000 has opened up the market to a number of low cost entry level tools based primarily on bar charts. There has also been an increase in the number of generally available niche systems offering enhanced; risk (eg Pertmaster), time/location and line of balance capabilities (eg DynaProjectâ„ ¢ and LinearPlus) and other functionality, that can operate stand alone or use data from and interact with the dominant systems such as Microsoft Project and Primavera. One very interesting development is a Russian tool called SPIDER. This software dynamically links time and cost (the original Kelley and Walker objective) within a managed risk profile. The loss of skills and control Prior to the 1980s Scheduling was a serious business; it used very expensive assets, required significant training and skill and was largely centralized and ‘visible’. Where manual scheduling was used, the saving in system costs was offset by the tedium of lengthy manual calculations. It simply did not pay to make mistakes! The arrival of ‘easy to use’ scheduling tools with a graphical interface radically changed the industry. Scheduling migrated to the desktop and the myth that ‘anyone’ can schedule (provided they knew how to switch on a PC) emerged. Many people learned ‘scheduling’ from using tools like Microsoft Project. There was no training or oversight and as a consequence, the average schedule is littered with ‘fixes’ allowed or encouraged by the tool. The trend has been towards a focus on computer processes and getting a schedule ‘looking right’ rather than analyzing a project to determine the appropriate duration based on appropriate resources and designing the schedule to be an effective management tool in the context of each specific project. As a direct consequence of this loss of skills, the importance of scheduling has dropped in most organizations and most projects run late! But the tide is turning†¦.. Current trends back to the future The requirement for effective ‘corporate governance’ is focusing management’s attention on project controls. The requirement for visibility, predictability and accountability of project performance can only be achieved by the introduction of effective corporate tools supported by skilled project schedulers7. The drive for visibility has been met by the arrival of powerful ‘Enterprise’ tools such as Primavera Enterprise and the suite of programs from WST including Open Plan and WelcomeHome. These integrated tools with effective data management and security ‘built in’ deliver the visibility and control needed for effective corporate governance (provided the tools are adequately supported). Additionally, the integrated nature of the tools makes project data visible and this visibility encourages enhanced quality. The drive for quality is creating a demand for skilled schedulers. This skills shortage is being helped by the spread of PMOsd and a renewed interest in scheduling training8. Many PMOs are also starting to recognize the need for, and develop skills in the ‘art’ of effective scheduling, as well as providing a home and career path for schedulers. The trend back towards a corporate view of schedule information and the requirement for skilled schedulers to operate the tools and provide effective support to project managers is being supported by the development of new standards. PMI will launch its ‘Scheduling Practice Standard’ in 2006, to augment the information in the PMBOK Guide. A longer term initiative is the work being undertaken by PMI’s College of Scheduling to develop and publish its ‘Scheduling Excellence Initiative’9. SEI is planned to develop and publish a comprehensive set of industry accepted best practices and guidelines for every aspect of project management ‘that touches a schedule, or that a schedule touches’. The consequence of these trends is that schedulers are once again in great demand around the world. The role of the scheduler is back! Conclusions The evolution of scheduling has been a fascinating journey: Kelley and Walker set out to solve the time-cost conundrum and invented CPM. For most organizations the resolution of time-cost issues is still in the ‘too hard’ basket (although SPIDER offers an interesting solution)! The PERT project invented the name ‘Critical Path’, and everyone else borrowed it. Fondahl invented a non-computer methodology for scheduling that is now used by every computer package worldwide! Whilst Kelley and Walkers CPM system was developed for computers and is now only seen as a manual technique. The changing role of the scheduler has been almost as interesting: The mainframe era saw scheduling as: o A skilled profession o Central to the success of projects The new ‘enterprise’ era sees scheduling as o A skilled profession o Central to the success of projects We have gone back to the future! III. Data and Analysis -Data Activity| Description| Predecessor| ABCDEFGHIJKLMN| Civil and StructuralFire Protection WorksMechanical WorksElectrical WorksPlumbing WorksAuxilliaryMasonry/WetworksMiscellaneous Walls ; FinishesMiscellaneousPainting WorksCeiling WorksFloor FinishesMechanical EquipmentElectrical EquipmentFire Protection EquipmentPlumbing Equipment| D, EB, C, EAAHH, IGFK, L, M| This Table shows the flow of activities in building basement 3. We were able to determine the activities by the given data. * CPM Network Crash Completion Time 9 months Crash Cost: Php 6, 197, 600. 00 Critical Path: B – G – L M IV. Conclusion This study investigates on the feasibility of project development thru the use of PERT and CPM techniques. Both aided the researchers in getting the critical path, optimum project completion time, and minimum project cost incurred after the optimum crash completion time. The critical path is the longest path of the project where it indicates the amount of time needed for the completion of the project. Thus the activities along this path must be accelerated in order to catalyze the project, On the other hand, when delays happen in these activities would cause a chain reaction of delays throughout the scheduling, etc for the rest of the project. Obtaining the optimum project completion time is done by crashing the network. Crashing the network refers to crashing a number of activities in order to reduce the duration of the project below its normal value. Based on the data obtained, this project accomplished in 13 months with a total cost Php 4, 596,400. 0. However if the project is crashed the soonest possible time is 9 months with a cost of Php 6, 197, 600. 00. V. Recommendation Though PERT and CPM considers the cost and completion time available it doesn’t really reflect how the real scheduling of a construction project is. It is only an ideal flow of activities. In current construction project activities usually starts simultaneously e. g. As soon as this first floor floor ing is done, they begin with the next floor not observing anymore the other activities to be done on first floor. Therefore the use of PERT CPM should be of initial study and not as a basis of overall scheduling of construction. VI. References Hillier and Lieberman. â€Å"Introduction to Operations Research†, Chapter 10 Project Management with PERT/CPM, 7th Edition Weaver, P. (2006) â€Å"A Brief History of Scheduling†, ; pmforum. org/library/papers/2006/A_Brief_History_of_Scheduling. pdf;. â€Å"PERT/CPM for Project Scheduling ; Management†, ;interventions. org/pertcpm. html;. â€Å"Pert Diagram and CPM†,

The Curious Case of Whet

The Curious Case of Whet The Curious Case of â€Å"Whet† The Curious Case of â€Å"Whet† By Maeve Maddox Here’s a question from Caro that cites a usage for whet that I’ve never heard: I have recently seen several people using the word â€Å"whet† in place of the word â€Å"wet†.   (In one case, I asked a friend if shed meant to say â€Å"wet† but she said it can also be used as a dirtier form for â€Å"wanton† I can only wonder what the friend understands by wanton. Both whet and wet have been in the language since Ango-Saxon times. whet: OE hwettan to sharpen† Even back then the word could have the figurative sense of â€Å"to encourage.† wet: OE wà ¦t moist, liquid, OE wà ¦tan to be wet. OE wà ¦ter, â€Å"water.† When I taught young girls in England, I often heard one of them say that So-and-So was â€Å"wet.† It meant that the unfortunate girl under discussion was â€Å"socially ineffectual† or, as they may be saying now, â€Å"wimpy.† I don’t often hear the word wanton in ordinary conversation. It can mean â€Å"lascivious† as in â€Å"that wanton hussy.† Youre more likely to hear someone refer to â€Å"wanton cruelty.† In the latter example the meaning is â€Å"merciless, unfeeling, inhuman†: Leaving those dogs tied up in the backyard when they moved was wanton cruelty. The earliest meaning of wanton was similar to the French expression mal à ©levà ©, â€Å"badly brought up.† Wanton was a word to use when referring to unruly or unsocialized children as Shakespeare does in Lear: As flies to wanton boys are we to the Gods. They kill us for their sport. Wanton was originally a two-part word: wan-towen. OE wan meant â€Å"wanting or lacking.† OE togen was the past participle of teon, â€Å"to train, to discipline.† The wanton child was lacking in discipline. Expressions with â€Å"whet† in the sense of â€Å"encourage† or â€Å"stimulate† whet one’s appetite: stimulate one’s desire to eat whet one’s whistle: clear one’s throat by taking a drink whet one’s anger: increase feelings of anger Expressions with â€Å"wet† wet one’s whistle: take a drink wet-nurse (1620): a woman hired to nurse another’s infant wet dream (1851): nocturnal emission wet blanket (1879): a person who brings down the spirits of others, (the way a wet blanket may be used to smother a fire). to be all wet (1923): to be in the wrong wetback (1924): illegal Mexican immigrant (wet because of wading the Rio Grande). Bottomline: Using whet as a â€Å"dirtier form of wanton† is totally bizarre. (But then, not being au courant with the latest slang, I may be all wet.) Want to improve your English in five minutes a day? Get a subscription and start receiving our writing tips and exercises daily! Keep learning! Browse the Misused Words category, check our popular posts, or choose a related post below:Regarding Re:50 Diminutive Suffixes (and a Cute Little Prefix)Oppose and Opposed To