Laith A. Hadidi

Integrated models in production planning and scheduling, maintenance and quality: a review

The integration in production planning, scheduling, maintenance and quality has gained much attention from researchers in recent years. These areas are usually treated independently, which yielded independent models for each function. It is widely believed that these separate models will provide suboptimal solutions, due to the fact that they are interrelated. Proper understanding of this dependency will open a new avenue for more integrated models, and result in significant savings in operational cost and improved efficiency for any production system. This paper reviews the literature on models addressing different aspects of integration in these areas. This integration is treated in two different ways in the literature. The first way is to present models where a model is considered for one function taking into account the other. These models are referred to as interrelated models. The second way is to simultaneously model two or more elements of the production system. These models are referred to as integrated models. The objective of this paper is to review research in both interrelated and integrated modelling of production planning, scheduling, maintenance and quality to identify possible future directions.

Joint job scheduling and preventive maintenance on a single machine

This paper considers the integration of production scheduling and preventive maintenance (PM) scheduling on a single machine that is subject to random failures. PM that restores the machine to an ‘as good as new’ condition is to be performed before the start of job processing, if needed. The objective is to determine the job schedule as well as PM schedule that minimise the total weighted expected jobs completion times. The problem is formulated to jointly model production scheduling and maintenance decisions as a mixed integer programme. Solving the model results in the optimum schedule of maintenance as well as production, which is usually determined independently.

An integrated cost model for production scheduling and perfect maintenance

Production scheduling deals with scheduling production jobs on a machine (single or multiple) in order to optimise a specific objective such as total weighted completion times or total weighted tardiness. The assumption that machines are always available for processing jobs is generally used in the production scheduling literature. In reality, machines often are unavailable due to preventive maintenance activities or machine failure. Production scheduling and preventive maintenance planning are interrelated, but are most often treated separately. This interdependency seems to be overlooked in the literature. This work integrates, simultaneously, the decisions of preventive maintenance and job order sequencing for a single machine. The objective is to find the job order sequence and maintenance decisions that would minimise the expected cost.

Practical implications of managerial decisions to integrate production scheduling and maintenance

This work discusses the practical implications of managerial decisions to integrate the scheduling of production and maintenance operations. Integrating both decisions will assure minimizing product holding costs and maintenance costs. In this paper we discuss the case involving a single machine processing a number of jobs differing in processing time requirements. The machine goes through preventive maintenance or corrective maintenance activities which in effect increases the total production cost. We present a modified version of the integrated model developed by Hadidi (Int J Math Oper Res 3: 395–413, 2011) and demonstrate its utilization under various conditions to emphasize the practical implications of the model. In practice, managerial decisions are highly affected by the cost parameters of maintenance, correction and holding costs.

A systematic approach for ERP implementation in the construction industry

AbstractThe objective of this paper is to provide a decision support tool that helps in prioritizing enterprise resource planning (ERP) modules’ implementation. The literature shows high risks of failure during the ERP implementation in construction industry. This research provides a systematic approach to have a successful ERP implementation in the construction industry. The provided approach of this research helps construction companies worldwide and specifically Saudi Arabia to better implement ERP projects. A case study approach is conducted with experts in ERP implementation at construction field in order to rank different ERP modules. This research develop a four step methodology to sequence the ERP module implementation. The first step defines the most common ERP modules in the construction industry. The second step defines the expected benefits of ERP implementation. The third step will define the importance index (I). Finally, the fourth step rank the ERP modules based on the global index that co...

Reliability for multiple units adopting sequential imperfect maintenance policies

Preventive maintenance literature provides so many models that address single unit systems. However, many real life applications deal with multiple-unit systems. This work deals with a sequential imperfect preventive maintenance model and extends it to consider multiple units. The model targets specific system reliability by determining the maintenance timing for each unit in the system. The model helps to optimize the maintenance management process for multiple-unit systems.

The effect of ISO 9001 implementation on the customer satisfaction of the engineering design services

Purpose ISO 9001 is an international specification that provides certification for quality management systems (QMSs) after careful external auditing. However, certified companies rarely evaluate their quality systems after being certified. The certificate needs to be renewed periodically where companies are encouraged to evaluate their gained benefits and improve their QMS’s deficient areas. The purpose of this paper is to provide a method of evaluation based on the level of customers’ satisfaction over five metrics (reliability, assurance, tangible, empathy, and responsiveness). Design/methodology/approach The methodology enables to benchmark the current level of satisfaction with prior levels of satisfaction before the ISO 9001 certification. The methodology is applied for the QMS pertinent to the design services (DS) for a large public company in Saudi Arabia. Three case studies were undertaken on the DS for large-scale construction projects. Findings The results were compared between year 2008 (total of 77 projects) and year 2011 (total of 39 projects). The results show that the ISO 9001 certificate may not always demonstrate an evidence of improving customers’ satisfaction levels and, hence, a gap analysis should be implemented to define possible areas of improvement. Research limitations/implications This work is limited to the construction industry. In specific, it addresses only the customer satisfaction related to the design management services. However, Saudi Arabia is known to host many large scale organizations that are heavily involved in international business trade. Hence, the authors believe that the Saudi industry can leverage their practices up to the international standards and similarly the international practices can accommodate some of the best practices in Saudi Arabia. Originality/value It is a general perception in the industry that ISO 9000 implementation will mean good quality products. This work provides the argument that the ISO 9000 implementation should be tested on a regular basis to validate this perception. It shows that in some cases the ISO 9000 did not improve the customers’ satisfaction and, hence, the need arises for gap analysis to modify the QMS.

Reliability improvement for electrical pneumatic arm loading system

This paper highlights the performance of electrical equipment and discovers any unspecified breakdowns at the electrical equipment. It focuses on the damages that are caused by electrical equipment failures. Moreover, it gives practical solutions and recommendations of how to improve electrical equipment reliability in arm loading system to prevent delay of oil shipment. The report also relied on field and sites observations to collect the required data. All information gathering was carried out through personal observations and deep search on data base available in the Company. The sites search covered the following areas; Power System Equipment Area. All the break down times were carefully detected and documented. The findings of the report supported the electrical equipment reliability.

Economic analysis for agility in manufacturing environment

This article is intended to model unpredictable change in an agile manufacturing environment. A model for unpredictable changes expressed by an agility index was developed and explained through numerical simulation. The model took into consideration the need for investing in agility depends upon the business circumstances and environmental turbulence. It shows that investing in agility increases the expected savings from changes and decreases the expected time a company needs to spend in dealing with change intelligently. The mathematical model is developed to evaluate the expected total cost through the four dimensions of change: cost, time, scope and robustness. This model supports the decision making process for justifying agility investment using change sensors analysis, and it aids in finding the optimal value of an agility index that minimises the expected total cost. It is found that there is an optimal value for an agility index that minimises the expected total cost for a certain production system.

Risk assessment and allocation in the contract for public works used in Saudi Arabia construction industry

Abstract This article aims to propose a new model to assess the Saudi public contract for risk sharing through the investigation of the perceptions and proposals of owners and contractors in Saudi Arabia on the statement of the clauses of the contract. The data collection tool used is a survey questionnaire comprising 70 items that refer to each clause of the Unified Contract for Public Works (UCPW) in Saudi Arabia. A sample size of 42 was determined using Kish’s formula (20 contractors and 22 owners) and a total number of 46 responses had been received. The results revealed that, in general, respondents did not believe that risk sharing exist in the Saudi UCPW. Moreover, 11 new areas of disagreement emerged from the proposals of the respondents. Using the Chi-square test, the data was tested for dependency on respondent’s type, and it was found that the number of risks allocated to each party is independent from the type of respondent.