Teklif birim fiyat usulü inşaat ihalelerinde dengesiz tekliflerin tespiti için puanlama yaklaşımı
An improved grading system-based model for detecting unbalanced bids during the tendering process
Yazar: SERHAN KIR
Danışman: DOÇ. DR. ATİLLA DAMCI
İstanbul Teknik Üniversitesi / Fen Bilimleri Enstitüsü / İnşaat Mühendisliği Ana Bilim Dalı / Yapı İşletmesi Bilim Dalı
Derece: Yüksek Lisans, 2019
Konu: İnşaat Mühendisliği = Civil Engineering

Özet:
Proje teklif bedelini doğrudan etkilemeden, planlanan yatırım sürecinde oluşabilecek miktar artışlarının istekliler tarafından öngörülerek, kasıtlı şekilde bu iş kalemlerinin birim fiyatlarında manipülasyon yapılarak veya zamana bağlı (erken ödeme / geç ödeme) etkenler nedeniyle, proje giderleri ve kârının iş kalemleri arasında dağıtılması neticesinde teklifin dengesizleştirilmesine, dengesiz teklif denir. Son yıllarda yapılan ihalelerde verilen dengesiz teklifler neticesinde karşılaşılan keşif artışları nedeniyle işlerin tasfiye edilerek ikmal ihaleleri kapsamında yatırımların tamamlanmaya çalışılması kamu kuruluşları açısından büyük sıkıntılara sebep olmaktadır. Yatırımların gecikmesi, hatta sekteye uğraması nedeniyle, yatırım sonucu hedeflenen hizmetlerin vatandaşa ulaştırılması gecikmekte, hedeflenen yatırım tutarının üzerine çıkılması nedeniyle kamu kaynakları etkin ve verimli kullanılamamakta, bu durum vatandaşların kamu kuruluşlarına güveninin azaltmakta, kamu çalışanlarının açısından ise maddi-manevi yaptırım sonuçları doğurmaktadır. Kamu kuruluşları açısından ihalelerde, dengesiz tekliflerin tespiti ve engellenmesi büyük önem arz etmektedir. Çalışma kapsamında öncelikle literatür analizi yapılarak, dengesiz teklifin belirlenmesine ilişkin uluslararası ve ulusal prosedürler incelenmiştir. Sonrasında 8 adet puanlama türü içeren dengesiz teklif tespit modeli oluşturulmuştur. Gerçek bir ihaleye ait metraj ve birim fiyat verileri ile 6 adet istekliye ait birim fiyat teklifleri kullanılarak oluşturulan model ile vaka analizi yapılmıştır. İlk puanlama kriterinde, isteklilerin tüm iş kalemlerine teklif ettikleri birim fiyatlar ile idarenin tespit ettiği birim fiyatlar karşılaştırılmıştır. İkinci puanlama kriterinde, isteklilerin tüm iş kalemlerine teklif ettikleri birim fiyatlar ile isteklilerin teklif ettikleri birim fiyatların ortalaması karşılaştırılmıştır. Üçüncü puanlama kriterinde, isteklilerin ve idarenin iş kalemi maliyeti ile yapı toplam maliyeti oranları karşılaştırılmıştır. Dördüncü puanlama kriterinde, isteklilerin vermiş olduğu birim fiyatlar sonucunda ortaya çıkan yapı toplam maliyetleri, idareye ait yapı yaklaşık maliyetinin yüzdesel olarak hangi aralıkta kaldıkları incelenmiştir. Beşinci puanlama kriterinde, istekliler ve idarenin riskli imalatlar toplam maliyeti ile yapı toplam maliyeti oranı karşılaştırılmıştır. Altıncı puanlama kriterinde, isteklilerin majör iş kalemlerine teklif ettikleri birim fiyatlar ile idarenin majör iş kalemlerine ilişkin tespit ettiği birim fiyatlar karşılaştırılmıştır. Yedinci puanlama kriterinde, isteklilerin majör iş kalemlerine teklif ettikleri birim fiyatlar ile isteklilerin majör iş kalemlerine ilişkin teklif ettikleri birim fiyatların ortalaması karşılaştırılmıştır. Sekizinci puanlama kriterinde ise, isteklilerin ve idarenin majör imalat toplam maliyeti ile minör imalat toplam maliyeti oranına bakılmış ve isteklilerin sekiz adet puanlama kriterine göre aldıkları toplam puanlar ile puanlama önem katsayısı neticesinde aldıkları ortalama puanlar belirlenerek modele ilişkin vaka analizi sonuçlandırılmıştır. Analiz sonucunda sözleşme imzalanan isteklinin en avantajlı ilk iki teklif içerisine giremeyerek üçüncü olduğu görülmüştür. Teorik inceleme açısından hazırlanan model mevcut mevzuat hükümleri açısından incelenmiş ve model-mevzuat uyumu açısından alınması gereken önlemler belirtilmiştir. Dengesiz teklifin engellenmesi açısından en önemli unsurun idare / işveren personelinin mümkün mertebe doğru metraj tespiti yapması, en azından makul olandan fazla hata yapmaması olduğu düşünülmektedir. Bununla birlikte idarelerin / iş verenlerin, ihale hazırlık çalışmalarında bir kurum kültürü ve denetim mekanizması oluşturarak, benzer ihalelerde tecrübeye binaen yapılan hataları minimize etmesi gerektiğinin büyük önem arz ettiği düşünülmektedir.

Abstract:
Unbalanced offer, can be defined as the unbalance of the proposal as a result of the distribution of the project expenses and profit among the manufacturing items due to the deliberate effect of the amount or amount increases in the planned investment process by the bidders, or by the manipulation of these work items or due to time dependent (front load / late load). In fact, unbalanced bidding models can also be defined as the mathematical techniques used by bidders to benefit from unregulated price ranges between work components. Unbalanced biddings effects negatively of construction values and construction times for Turkish Public Corporations and employers. These problems cause legal problems and reduce people's confidence to public investments. Due to the delay in investments or even disruptions, the delivery of the targeted services to the citizen is delayed due to the investment, and because the targeted investment amount is exceeded, the public resources cannot be used effectively and efficiently, this situation reduces the confidence of the citizens in the Public Institutions and results in material-moral sanctions for public employees. Determination and inhibition of unbalanced biddings are main goal for public corporations and employers due to result of their investments. The unbalaced bidding can be investigation in two main titles. First of it is due to time dependent as front or late load and second title is due to incorrect quantities. In the most common method of early payment in unbalanced proposals, the bidders aim to pre-load by keeping the unit prices of work items to be higher. In the unbalanced bidding method called front load, it is aimed to increase the unit price proposals of work items to be produced at the end of the work by the bidder and to make maximum use of the price difference payments from inflation. In order to apply this method, there will be a provision stating that the price difference will be paid in the contract of the work. The incorrect quantity unbalanced bidding can be defined as the manipulation of the errors predicted by the bidders in favor of the tenderer without affecting the final proposal in the approximate cost quantity data calculated by the Administration / Employer in the works which are tendered as unit price. The main reasons for the discrepancies in the tendency to increase or decrease in the quantities are; The engineer who calculates the exploration quantities cannot know the ground parameters or misinterpretation, Inaccurate interpretation of the size profile and current data used by the engineer calculating the amount of exploration, or misinterpreted by the engineer, Calculation of the amount of quantity by missing or defective projects, revision of the accounts following the emergence of the actual project which must be prepared in the implementation projects prepared by the contractor after the tender and approved by the administration, Trying to raise the preparation of tenders for limited periods, The projection of the amount of the engineer can not be expected to increase in the project due to the lack of sufficient knowledge, equipment and experience, Due to the personal (special) distress of the engineer who calculates the quantities. 
General opinion made the lowest bid in the public sorporations in Turkey, it was regarded as the most economically advantageous bid contract with the lowest bid is made except under special circumstances if its described. The main purpose of this to make the most of the work with the cheapest offer, not to take risks in possible reviews. When the bids made under the Law No. 2886 are examined, it is seen that this method has not been very successful or even abused when it is seen that the works have been spread over decades and due to the flexibility in the increase of exploration, the works have been completed on much of the contract price. Within the scope of the Law No. 4734; At the initiative of the administrations, it has been tried to prevent this by giving the opportunity to make maximum 20% exploration increase in the works with unit prices and maximum 10% in the turnover lump sum works. In last years, Administrations are expected to increase with the work items that are expected to increase as a result of past experience and the work items which are the weight of the work are prevented from being given unbalanced bidding by the bidders and it is aimed that the works will be completed and put into service at least within the limits of the legal work increase determined by the law. Since 2016, tenders have been issued by the State Airports Authority of Turkey on the basis of the unit price bidding procedure, in which all scoring criteria are issued under the heading of non-price elements. 
American Association of State Highway and Transportation Officials (AASHTO) conducted a 2004 study on Unbalanced Bidding Methods in the USA. In the California Department of Transportation, the unit prices of each business item proposed to determine whether a proposal is unbalanced are compared with the values determined by the personnel of the administration and the bids submitted by the other bidders. In Washington Department of Transportation and Wisconsin Department of Transportation, the unit price values of the business items in a proposal are considered to be a significant unbalanced offer if they are 50% greater or 75% smaller than the offer of the lowest bidder. In the Oregon Transportation Department and Vermont Transportation Unit, the unit price quotations of the bidders are compared with the unit price determinations prepared by the administration. In case of large differences between the values, the administration reserves the right to revise all bidders. In the Transportation Department of Alabama Transportation Department and Colombia Region, the unit prices determined by the administrations are compared with the unit price proposals submitted by the bidders. In the Maine Department of Transportation, the unit prices determined by the Administration and the unit price proposals submitted by the bidder with the most advantageous bid are compared and evaluated whether the proposal is unbalanced. In the Nevada Transportation Department, the unit price proposals of the bidders are compared with the unit price determinations prepared by the administration. In case of big differences between the values, the proposals are reviewed by the President of the Tender Commission and the Approximate Cost Determination Commission. In the North Carolina Transportation Department, the unit price quotations of the tenderers and the unit price determinations prepared by the administration are compared with the bids of the tenderers. Bids that are above or below reasonable are considered unbalanced bidding. In the Florida Department of Transportation, the bell curve for the bids submitted by the tenderers is established and the reasonable range of offers is determined. The offers outside this range are examined in detail. In the Texas Department of Transportation, the unit price quotations of the bidders are compared with the values determined by the administration. The work items larger than 5% of the bid value are considered as the main business items and the values given for these items are + 100% or - 50% for the value determined by the administration and + 200% to 75% for the other business items accepted as unbalanced bidding. In Toronto, the Administrators may consider this proposal unbalanced if it considers that the tenderers do not represent a lower or reasonable value than the unit price values of some items of business.
Within the scope of the study, firstly the literature analysis was conducted and the international and national procedures for the determination of the unbalanced proposal were examined. Afterwards, an unbalanced offer determination model was formed which includes 8 scoring types. The model analysis was performed by using the unit price data of a real tender and unit price quotations for 6 bidders. In the first scoring criterion, the unit prices proposed by the bidders for all work items and the unit prices determined by the administration were compared. In the second scoring criterion, the unit prices offered by the bidders to all work items and the average prices of the bidder's unit prices were compared. In the third scoring criterion, the cost of work item and structure total cost of bidders and administration were compared. In the fourth scoring criterion, the total costs of the building resulting from the unit prices given by the bidders and the approximate cost of the construction cost of the administration are examined. In the fifth scoring criterion, bidders and administration compared about the total cost of risky objects in construction costs. In the sixth scoring criterion, the unit prices proposed by the bidders for the major work items and the unit prices determined by the administration for the major business items were compared. In the seventh scoring criterion, the unit prices offered by the bidders to the major business items and the average of the unit prices offered by the bidderss for the major business items were compared. In the eighth scoring criterion, the majör and minor manufacturing total cost of the bidderss and the administration was examined with the ratio of the total production cost of the bidderss and the total points received by the bidders according to the eight scoring criteria and the average scores obtained as a result of the scoring weight coefficient, and the case analysis for the model was finalized. The significance coefficient for scoring 1,2,4,5,6,8 was 10%, for scoring 3 and 4 for 20%. 
As a result of the analysis, it was seen that the contracted bidder (Bidder 3) could not enter the two most advantageous first two bids and was the third. When the total points are examined, the most advantageous of the first two bids, 53,69 points, bidder 5 and 52,12 points, the bidder 1, contractor (bidder 4) had 49,56 points and took the 3rd place. Considering the scoring significance coefficients, it is seen that the most advantageous first two bids, which do not change the ranking, belong to the bidder 5 and the bidder 1, and the biddder 4 (the contractor) is in the 3rd place. Although, as a result of the tender made by State Airports Authority of Turkey, the contract was signed with the tenderer 4 as the most advantageous bid, it is possible that the tenderer is not offered the most balanced bid as the results are seen above and the tenderer is not offered the most balanced bid. It is seen that the prepared model gives important results in the determination of unbalanced proposal as a result of testing with actual tender data. 
The most important factor in preventing unbalanced bidding is that the administrative / employer's personnel should make the correct quantity determination as much as possible, but not more than the reasonable one. However, administrations / employers should establish a corporate culture and control mechanism in the tender preparation studies and minimize the mistakes made in experience in similar tenders. In addition to the existing 8 scoring criteria; It is considered that 2 additional scoring criteria may be revealed as a result of the examination of the work experience documents submitted by the bidders in the tender folders and the total risky bids submitted risky by the administration and the average of bidders to the risky products. In particular, because the work experience of the bidders is of great importance in terms of the competence of the job, it is considered that not only in terms of qualification but also in terms of rating criteria.