Investigation of Cost Control Measures for Main Contractors in Construction Projects

استنادًا إلى بحث سابق للمؤلفين، تم تحديد (59) عاملاً من العوامل المؤثرة في كلف مشاريع التشييد، تتضمن (13) عاملا هي أكثر العوامل تأثيرًا منها (10) عوامل من المرجح أن يسيطر عليها المقاولون الرئيسيون. تم في هذا البحث تحري تدابير السيطرة التي يرجح أن تكون في أيدي المقاولين الرئيسيين وفقا لآراء (30) من المهندسين العراقيين من ذوي الخبرة العالية. تم اجراء مسح استباني يتضمن (55) اجراءً للسيطرة على العوامل الأكثر تأثيراً على الكلفة. وتم ترتيب هذه الاجراءات باستخدام مؤشر الأهمية النسبية. فتبين لأجل السيطرة على الكلفة بشكل أفضل، أن على المقاولين ضمان: استخدام تقنيات ووسائل حديثة لرفع إنتاجية العمال، ووضع قواعد ملزمة للأداء الحسن للمقاولين الثانويين، والالتزام بالصيانة الدورية لتحسين أداء المعدات، وإدامة التخطيط السليم للموقع باستخدام تقنيات دراسة العمل، واختيار مدراء مشاريع مؤهلين، واستخدام تقنيات تخطيط وجدولة حديثة، وتأمين مواقع مناسبة للخزين الاحتياطي للمواد خارج موقع العمل، والتخطيط المسبق لمواصفات المعدات ومهارات العمال، واختيار موردين موثوقينBased on previous research by the authors, (59) cost control factors in construction projects were identified in which (13) were considered as the most influential factors. In this research, control measures that are potentially within the hands of main contractors were investigated according to the opinions of some Iraqi professional engineers of high experience. A questionnaire survey consisting of (55) control measures for the (13) most influential factors were suggested. When ranking those measures, based on the highest (RII), it was found that contractors should focus on; using modern techniques and tools to improve labor productivity, using modern design programs to give clear visualization to the owner so changes is reduced, setting solid rules to attain good performance for contractors, ‎S/C and ‎suppliers, paying liabilities on time to avoid shortage of funding, insure periodical maintenance to enhance equipment performance and lower downtime, integrity and anti-corruption, using work study techniques to insure proper site planning,  proper selection of project managers, using modern planning and scheduling techniques, prepare suitable safe off-site locations for backup material storage, insure previous planning for equipment specification and labor skills, insure selecting reliable suppliers

Modeling the Completion Time of Public School Building Projects Using Neural Networks

The Ministry of Education in Iraq is confronting a colossal deficiency in school buildings while stakeholders of government funded school buildings projects are experiencing the ill effects of extreme delays caused by many reasons. Those stakeholders are particularly worried to know ahead of time (at contract assignment) the expected completion time of any new school building project. As indicated by a previous research conducted by the authors, taking into account the opinions of Iraqi experts involved with government funded school building projects, nine major causes of delay in school building projects were affirmed through a questionnaire survey specifically are; the contractor's financial status, delay in interim payments, change orders, the contractor rank, work stoppages, the contract value, experience of the supervising engineers, the contract duration and delay penalty. In this research, two prediction models (A and B) were produced to help the concerned decision makers to foresee the expected completion time of typically designed school building projects having (12) and (18) classes separately. The ANN multi-layer feed forward with back-propagation algorithm was utilized to build up the mathematical equations. The created prediction equations demonstrated a high degree of average accuracy of (96.43%) and (96.79%) for schools having (12) and (18) classes, with (R2) for both ANN models of (79.60%) and (85.30%) respectively. It was found that the most influential parameters of both models were the ratio of the sum of work stoppages to the contract duration, the ratio of contractor's financial status to the contract value, the ratio of delay penalty to the total value of contract and the ratio of mean interim payments duration to the contract duration