Yapım yönetiminde kaynak planlama yaklaşımları ve kompüter destekli çoklu proje programlama

Abstract

Günümüzde, teknolojinin ve yapım tekniklerinin büyük bir hızla gelişmesi, üre time kalite ve hız kazandırmasının yanısıra, pekçok yenilik ve olanağı da beraberinde getirmiştir. Boyutlarını büyütmeye eğilimli olan firmalar bu olanaklardan yararlana rak, tek bir projeyi tamamlayıp diğerine başlamaktan çok, birden fazla projeyi aynı pe riyotta başarılı bir şekilde yürütmeyi amaçlamaktadırlar. Bununla birlikte, parasal kaynakların kıt, zamanın da çok değerli olduğu düşü nüldüğünde, kaynakların en rasyonel biçimde kullanılmasını sağlayacak bir yönetim anlayışı ve programlama tekniğinin gerektiği açıktır. Farklı proje koşullarında aynı yaklaşımların söz konusu olması düşünülemeyeceğinden, firmanın içinde bulunduğu koşulların ve yürütülecek projelerin gereksinimlerinin çok iyi analiz edilmesiyle kuru lacak bir sistemin, maksimum faydanın sağlanmasında atılacak ilk ve en önemli adım olduğu unutulmamalıdır. Yönetim anlayışının yanısıra, projelerin plan ve programının hazırlanması aşamasında da projenin boyutları ile kapsam ve niteliği, gözönünde tutul ması gereken önemli noktalardan biridir. Araştırma kapsamında ele alınan çoklu projeler de bu şekilde farklı yaklaşım ve tekniklerin gereksinildiği ortam ve koşullan yaratırlar. Bu tez, yakın geçmişte bilimsel bir temele oturtulan "Çoklu Proje Programlama" (MPS-Multi Project Scheduling) yaklaşımının karakteristiklerinin ve uygulama ilkelerinin incelenmesini amaçlayan bir çalışmadır. Tek projenin söz konusu olduğu durumlardaki organizasyonel yapının, planlama ve programlama yaklaşımının ve raporlama tekniğinin, çoklu proje ortamla rında kullanılabilirliğinin sorgulanması, yönetimsel anlamda ortaya konulan teorinin pratikte ne gibi sorunlarla karşılaşacağının belirlenmesi ve bu problemlerin çözümünde izlenmesi gereken yolun incelenmesi, araştırma kapsamında ele alınan başlıca ko nulardır. Çoklu proje programlamasının, birbirlerine çeşitli ilişkilerle bağlı farklı fonksi yon gruplarının ya da aynı kaynak havuzunu paylaşmak durumunda olan projelerin bir arada ele alınarak programlamasının yapılmasına ilişkin bir yaklaşım olduğundan hare ketle, bu gibi durumlarda kaynakların en etkin şekilde nasıl kullanılabileceği sorusuna çözüm aranmaktadır. Çünkü, mevcut kaynaklar ve yönetimsel dikkat için rekabet ha linde birden fazla projenin bulunması, çoklu proje ortamlarında kaynak planlama ve programlamasına çok daha fazla önem verilmesini gerektirmektedir. Kaynak kulla nımlarında kapasitenin aşılmasına yol açan çakışmaların ve kaynak yetersizliklerinin çözümlenmesinde gözönüne alınan kriterler, eylem önceliklerinin yanısıra proje önce liklerini de içermekte ve kaynak dengeleme işlemi, çoklu proje kaynak programlama sının ayrılmaz bir parçası olarak karşımıza çıkmaktadır. Son olarak, bu denli karmaşık ilişki ve işlemlerin ele alınmasının ancak kompü- ter desteğinin sağlanmasıyla mümkün olabileceği vurgulanarak, bu destek tüm yönle riyle ortaya koyularak, problemi ele alış biçimleri ve sundukları olanaklar bakımından, yaygın olarak kullanılan software paketlerinin birkaçı incelenmiştir.

Construction industry always searches for using money and time in the most effective way. Whatever size, workscope and technology of the production are, time and money are the main factors for defining the targets. A key element to successful construction management is found in a detailed scheduling system that provides a mean for planning, assessing progress, and controlling a project from original conception through completion of construction. In any type of project, from research and development to construction, the amounts of resources required to complete the project on time and within budget is an extremely important consideration. Resources require outputs of capital and time that are not always available in the amounts that management would like. Even if a company could obtain unlimited amounts öf resources, it may not have the supervision or facilities to handle them efficiently. Staffing a project efficiently is one of the toughest decisions facing management. A "resource" is a person, or equipment item that expends effort to do work. Resource scheduling defines, what specific resource, should work on which specific task, using which skill, at what level of effort, working what percentage of time and between which dates. Steps of a resource planning are: 1. Resource allocation: Defining the resources required to accomplish each activity on the network plan. 2. Resource aggregation: Defining the total amount of resources required for the project, in each time period, according to the plan and schedule. 3. Resource availability: Defining the resources which can be made available during each time period. 4. Resource leveling: Comparing resource requirements with resource availability to identify shortfalls, and reschedule the activities to assure that resource requirements will not exceed availability. 5. Schedule resource requirements: Preparing a schedule for the provision of project resources. Resource scheduling is not only the key to successful project, it is also a key to successful companies. Good resource scheduling is the basis for maximizing the productivity of people and equipment while minimizing their cost. In most situations there are labor and equipment shortages, and although enough labor may be available complete the critical jobs on time, there may not always be enough workers to do all VI noncritical jobs on time. Resource leveling technique is used to produce a solution to the problem. The resource allocating problem in scheduling has been studied in hundreds of articles. The majority of these articles deal with fixed-limit resource scheduling. In fixed-limits resource scheduling, there are definite, nonexceedable limits on the amounts of resources available. The scheduling objective is to minimize the project duration given the resource constraints. The decision variables of this problem indicate how the project activities are to be sequenced. The sets of constraints are usually based on some of the following:. Upper limit for resource availability. Precedence restrictions. Activity splitting allowances. Preemption of activities. Project deadlines. Resource substitutions. Partial resource assignments. Concurrent or mutually exclusive activity requirements On the other hand, meeting the project due date is extremely important in many industries. Equally important is accomplishing this in a cost effective manner. This type of leveling is "time-constraint resource leveling" that preserves the schedule end date and attempts to reschedule tasks to minimize the extent of the overload. These problems that are faced in a single project planning, are also exist in multi project situations. The aim of this study is to describe multi-project environment and explore the needs of multi-project scheduling. Where companies are handling several projects at the same time and where the resources must be shared between projects, it is necessary to integrate the planning, programming and control of these multiple projects. It is rare to find a project that exists by itself without interaction with other projects. The multiproject environment commonly found in many large organizations imposes complications at the project manager level, and at each level of the organization. The basic problems result from competition between projects for resources and management attention. Multi-project management is a centralized approach and strategically decision to be taken at management level of an organization. Location and responsibility of the multi-project manager can change due to size, scope and number of subprojects. Organizational structure also can be different. The higher order objectives of multi-project management, in comparison to managing a single project include:.Completion of all projects to best achieve the overall goals of the organization. vn . Determination of both long-term and short-range priorities between projects to enable appropriate decisions regarding allocation of limited resources.. Acquiring and maintaining an adequate supply of resources to support all projects, including people, facilities, material and capital; but at the same time assuring that these resources are gainfully and efficiently employed in approved, productive work required to complete the projects.. Integrating these multi-project requirements with other ongoing activities not related to projects..Developing organizational patterns and management systems to satisfy the ever changing project needs on one hand and to provide, on the other hand, organizational stability, professional development, and administrative efficiency for persons managing and supporting various projects. At appropriate levels in the organization, the multiple project requirements and priorities must be bought together to assure that all projects are completed so that the maximum benefits are obtained for the entire organization. The need for some means of integrating these multi-project requirements is frequently not fully recognized. The result is that a number of projects are individually managed by different parts of an organization, with a great deal of effort being exerted by the various project managers to win every competition with the other projects' resources needed by the projects are not sufficient to satisfy them all. There are three types of situations in which a multiple project schedule must be prepared, and there is a method to handle each one: 1. When a project manager wishes to combine dependent subprojects to create a detailed plan for the whole project. (Each project may have its own pool of resources.) 2. When the multiple project manager wishes to combine independent subprojects in order to create a detailed multiple-project plan. (Each project uses the same pool of resources.) 3. When subprojects must be summarized to create a management level multiple project plan. (Each project may or may not use the same resources.) If there is a a very big project which has many different functional groups or several projects that share the same pool of resources, these project can be brought together to create a multi-project plan. A multiple project activity and resource schedule must:. Schedule tasks realistically so the requirement for resources does not exceed availability..Provide early warning of the need to reschedule deadlines, change workscopes, increase resources, or work overtime. vm .Provide specific information on the current and plant workload for each resource, including all currently scheduled projects.. Be responsive to constant changes in workload, priorities resource availability.. Be consistent with project priorities. In a situation where several projects are competing for limited resources, the need for a method of determining and communicating the relative priority of each project is easily recognized. Unforeseen problems or needs can cause short-term conflicts even in the most thoroughly planned projects. When these occur, the person allocating a limited resource the one or the other project must have accurate knowledge of their current relative priorities. While the relative importance of these factors will vary, depending on the organization and the type of the project involved, the following list includes most of the factors important in setting priorities:. Completion date and its proximity. Penalty risks. Customer. Competitive risks. Technical risks. Management sponsor. Return on investment. Magnitude of cost, investment and/or profit. Impact on other projects When a large number of resources shared between multiple projects, it will be necessary to carry out fully integrated planning as there will be too many complex interactions between project an resources. If this was attempted on an individual function basis it would require many interactions and people would become confused. Automatic computer based resource leveling would have to be carried out with project priorities set by the planner, with limited human-machine interaction. This would produce a multi-project plan that makes sensible use of priorities to achieve the objective of all the projects and the company as a whole. Included among the factors that determine when a computer should be considered for use are the following: -Size of the project -Complexity of the project -Type of analysis required -Frequency with which the project needs to be updated Computer has become an absolutely necessary tool in implementing project management techniques and also in multi project scheduling but, it's not enough to provide only software packages for programming and controlling the projects. Software, hardware and user are the main elements of the "Management Information EX Computer has become an absolutely necessary tool in implementing project management techniques and also in multi project scheduling but, it's not enough to provide only software packages for programming and controlling the projects. Software, hardware and user are the main elements of the "Management Information System". In multiproject management, it is more important to establish such a system that works effectively. Software is an element of the management information system and present specific features to manage and schedule multi projects. They are; outlining, standard resource and cost lists, multiple calendars, complex calendars, multiple-project combination techniques, choice of scheduling methods, use of priority multiproject resource scheduling, complex resource allocation and availability, export-import. In the last chapter, some of the software packages are analyzed according to their multi-project scheduling features. These are; Primavera Project Planner, Time Line, Microsoft Project, Super Project. A package that has a specific purpose also examine because of its multi-project programming approach.