OPTIMIZATION OF AUTOMATED PRODUCTION CHAIN USING CRITICAL PATH METHOD

Transcription

1 Jurnal Karya Asli Lorekan Ahli Matematik Vol. 6 No.1 (2013) Page Jurnal Karya Asli Lorekan Ahli Matematik OPTIMIZATION OF AUTOMATED PRODUCTION CHAIN USING CRITICAL PATH METHOD Abdul Talib Bon 1 & Nurul Haerani Mohamad 2 Faculty of Technology Management and Business, Universiti Ton Hussien Onn Malaysia Parit Raja, Johor, Malaysia 1 talibon@uthm.edu.my Abstract : Manufacturing sector plays crucial role in boosting the economy for a country. In order to obtain the world class performance, many companies took initiatives in enhancing their qualities and productivities as well as minimizing their cost at any possible cost. Automation techniques in industries have shown the effectiveness in term of usage especially in manufacturing sector. It helps to simplify the manufacturing and production s processes as well as optimizing the period of production s processes. Therefore, working processes template is important to obtain that obtain that objective. Critical Path Method, CPM has been claimed as one of the tool in planning or designing working process. This method has been used in scheduling project. CPM concept take cares of between costs and the dateline of a project that need to be completed whereby it will be the factor for this research. This research is too profound the essential of CPM from the manufacturing s spectrum. This research focuses on the conveyer line out in one of the electronic manufacturer which producing keyboards as their main product. Information is gathered through observation and interview. The outcome of the research has been analyzed by using POM-QM for Windows Version 3, Project Management (PERT/CPM) Module software. The analysis has been carried out to fulfill the objective of this research. Based on the analysis, the researcher has came out with few ideas of improvement as a guideline for the keyboard manufacturer as well as for those who counterpart in the manufacturing industries. Key Words: Optimizing, Critical Path Method, Keyboard manufacturer, Automation. 1. Introduction In these present, industrial automation shows the effectiveness in manufacturing aspect. Automation is defined as implementation of work or production using equipment such as machinery, machine tools, computers and so forth. Automation is able to work faster and control itself without humans assistant (Vanderspek, 1993). Scheduling of activities involving the distribution of works into different activities and makes an estimation of time and resources that will be used to complete each activity as well as to improve the productivity. Taking into account the constraints of time and resources, implementation of the activities must be scheduled to ensure resources are used optimally. Critical Path Method (CPM) was essentially developed in 1950 as a means or method of planning projects in industrial engineering and management science. It has been widely used for projects such as construction, civil engineering, marketing, ship development, product design and installation of equipment (Falconer, et al, 1993). CPM is a technique developed by the DuPont Company, Remington Rand and Mauchy Associates (Nicholas Steyn, 2008) to help managers to manage, maintain and control large projects and complex. It is a networking technique that uses only one time per activity and factor analysis of the project network is used to forecast total project duration. CPM concept is concerned about the consideration of cost and date of a project to be completed. It emphasizes the relationship between the use of labor or other resources to minimize the duration of a job in a project. With that amount of time required to complete various aspects of the project is estimated to be known more accurately. Under this concept, the work is not necessarily focused but the basis of this model is the arrows. Each arrow represents each activity within the project while the tail of the arrow represents 2013 Jurnal Karya Asli Lorekan Ahli Matematik Published by Pustaka Aman Press Sdn. Bhd.

2 Abdul Talib Bon & Nurul Haerani Mohamad the start of an activity and the head of the arrow represents the work terminated. Figure compiled arrows indicate the sequence in which the planning activities that will be completed. Critical path to complete the manufacturing process is a series of activities which determines the early production process that can be completed. Critical path is determined by identifying the longest path or the longest period of time through the network diagram. 1.1 Background of the Study Various industries began to compete to achieve the maximum profit. optimize the operations production time is one of the means used by companies or organizations established in the industry to continue maintain in the industry. CPM is a method used in industry or other sectors to optimize the time of activity but it depends on time and cost. This study was held at one of the electronic components manufacturing factory. This plant produces two main products which are electromagnetic relay coils and the production of the keyboard (keyboard) for desktop and laptop computers. The study was conducted on the keyboard production line. Keyboard manufacturing process involves several numbers of operations starting from gear link alignment until packaging inspection. In the production of this keyboard, there are three primary workstations and each workstation has their own specific processes. 1.2 Problem Statement In order to achieve nation developed status by 2020, the manufacturing industries become one of the main generators of economic growth in Malaysia. Therefore, the development of the manufacturing sector should be transformed into a more dynamic, high value-added, capital intensive and automation technology-oriented in order to achieve higher productivity growth and competitiveness at the international level. Looking at the changing of business environment, it the organization and management have to be sensitive and flexible into changing needs. Challenging environment and increasingly business demands will lead the decrease profit of an organization. This phenomenon requires the management to be more prepared with a variety of effective strategies for dealing with any challenges that lie ahead. Te approaches and developments should be taken into account. Less costs, efficient management and operation of a dynamic and a more systematic organization should be emphasized. Therefore time and costs management should be emphasized in the reform and use an organization system. In addition, the optimization of the manufacturing process chain also contributes to the level of production quality. If the activity level of project or time can be optimize, the production rate increasing while production costs are reduced. The studies of CPM have proven by Zender (1993) in the medical field. This study highlighted and focused on identifying the critical path in the production line at the researcher s keypad factory. Mostly, CPM was done outside the country in other sectors. So this situation encouraged researchers to carry out this study on manufacturing and focused on the production line at one of keyboard manufacturing factory. Hopefully, this study will help Malaysia organizations to practice and perform CPM in their production systems while optimize the time of project activity and additionally stabilize the quality production of products as well as optimize the costs. 1.3 Research Question Does Critical Path Method (CPM) can optimize the processing time at the keyboard manufacturing production line in one of electronic manufacturing factory. 1.4 The Objectives To identify whether Critical Path Method (CPM) can optimize the processing time at the keyboard manufacturing production line in one of electronic manufacturing factory? 35

3 Jurnal KALAM Vol. 6, No. 1, Page Scope of the Study This study focuses on the keyboard production line at a manufacturing factory. 1.6 Importance of Study Through this study, hopefully can assist and provide information to the manufacturing sector in order to know the importance of CPM while introducing this method as well as how to implement this method effectively. In addition, this study can help the manufacturing sector to be more sensitive regarding to the improvement organizational performance and productivity. 2. Literature Review 2.1 Automation in the Manufacturing Industry Automated appeared since 1936 and comes from the Greek "Automotos" which means to move themselves (selfmoving) and the Latin "Ion" which meant permanent (a state). According to Hitomi (1994), the definition of automation is: "A process of moving its own production which is controlled and operated by the people." The use of automation has been developed since the invention of numerical control (numerical control) in 1952 (Hitomi, 1994). At present, the use of automation in the manufacturing industry is flourishing due to the increased use of technology. The importance of this automation can be viewed from several aspects, which increase labour costs, increased demand, global competition, the use of space within the plant and ease the movement of the work piece (Nutt, 1970). 2.2 Critical Path Method (CPM) According to Heizer, Render (2006) CPM is a techniques developed in the 1950's to help managers manage, maintain and manage large projects and complex. CPM was formed in 1957 by JE Kelly of Remington Rand and MR Walker from Duport which manages the building and control of chemical plant at Duport. CPM is a network technique that uses only one time per activity factors to allow managers to control, manage and schedule a large and complex project. Peter Stelth (2009) says that CPM is also defined as a technique for analyzing the activities of the project by identifying the longest path through the network project. CPM is a methodology management that is used since the 1950's with the main objective was to determine how well its application of this method to optimize the time needed to carry out a project or process. CPM analysis is also a way to identify if there are alternative routes or plan that can be taken to reduce the obstruction and interference that may arise during the project or process being carried out (Rivera & Duran, 2004). 2.3 Planning Planning can be defined as a process of thought to make things done in future. In manufacturing operations, planning is a process of thinking about the selection method of operation and production of appropriate and order the work or processes to be followed for the conduct of the production process. Method and sequence of the suitability of the work or the process can be completed with the most economical cost within the time specified and meets the needs of customers and organizations (Abdul Hakim Mohamad, 1990). Various methods and tools used in planning as Bar Chart, Critical Path Method, Scan Line, Primavera, Microsoft Project, etc. 36

4 Abdul Talib Bon & Nurul Haerani Mohamad 2.4 Production Lines in the Manufacturing Sector Production line is a process repeated in each product through the process operations, machinery and other equipment in the same in-out sequence. The process involves the production is the production of goods or services. It involves the conversion of raw materials into semi-finished goods or finished goods for use by consumers. The process involves the production of smaller subsystems to form a larger system. Studies have been conducted in connection with CPM, Peter Stelth & Proffessor Guy Le Rot (2009), Yi-MinDeng (2010), ME Lin, G. Koley, W. Liu & D. Biswas (1999), and Dr. Ron Davis (1995) and Tarun Gupta (2003). Peter Stelth & Proffessor Guy Le Rot (2009) that examines the use of CPM in analyzing a project and realized the two important variables in any project are time and cost. In addition, increasing efficiency and productivity must always be a factor in implementing any changes. In Dr. Ron Davis (1995) studies, has concluded the use of CPM is widely used in various sectors such as automation, construction, education and training, new product development, risk management, marketing and sales, and many other sectors. Next, a study conducted by G. Koley, W. Liu & D. Biswas (1999), describes the organizational structure requirements in the design and operation of the CPM. Lana Shekim (1993) in his study states that the number of hospitals using CPM to increasing quality and efficiency of patient care has increased rapidly. Use of CPM in the manufacturing sector is also known as the Manufacturing Critical-path Time (MCT), (Paul D. Eriksen, Nathan J. Stoflet & Rajan Suri, 2007). According to the study of Paul D. Eriksen, Nathan J. Stoflet & Rajan Suri (2007), entitled Manufacturing Critical-path Time (MCT): The QRM Metric for Lead Time, concludes that "you can not reduce something if you can not even agree how to measure it." Based on the observations of previous studies, there is no doubt that the use of CPM in the manufacturing sector became an important. CPM can assist the manufacturing sector in optimizing the time of production, but must take into account the factors of production time and costs. Therefore, this study hopes to provide a clear picture of how the use of CPM can to help optimize the automation of the production chain in Malaysia. 3. Methodology 3.1 Design Review In this study, the elements of the activity process are the dependent variable, while the production rates are independent variables. This means that elements of the production activities will impact on production rates. The method used to obtain data is a record of the observation of keyboard production line at an electronics factory, which produces Parit Raja. Data will be recorded and analyzed using software production management operations, POM-QM for Windows (Version 3), Project Management (PERT / CPM) Module. Through this software, the analysis will be made in a particular table and then be expressed in terms of access arrows (AON: ACTIVITY-ON-NODE) and the Gantt chart to facilitate the study interpret and draw conclusions title. 3.2 Establishing Objectives and Scope of Study The objectives stage is important to ensure that the real objective of a review of your choice. The scope is used to make the limitations of a study. Forming the scope of the study is important for determining only the respondent only certain areas of research will be focused. The objective of this study was to determine the use of critical path method, CPM to optimize keyboard manufacturing production period in an electronic factory production lines.. 37

5 Jurnal KALAM Vol. 6, No. 1, Page Method of Observation Observation was done on the production line system. Information and data will be taken in the use, operation and production of the system layout. Records and inspection list will also be seen and studied. 3.4 Data Collection Primary Data Data collection for this study by observation of production processes and records of previous production through operations manager research organization. Data obtained from the observations and temebual operations manager called the primary data, which means that the first source of evidence or the results of a study langung. Stage of data collection are also important for accurate data collection is necessary to ensure that a study be conducted were justified and that is due to substantial evidence. The two sources were used to collect the necessary data in this study Secondary Data In achieving the objectives of the study, relevant information in making use of CPM derived from secondary data. In addition, the data is derived from written records such as journals and other reference materials. The information obtained is collected to facilitate the process of analyzing the data while achieving the objectives of the study Activities and Events and Network According to Heizer, Render (2006) in the determination of CPM, dividing the whole range of projects or production processes to the activities through a structural breakdown. Event was the site of the beginning or end of an activity. It was a long time. While the activities are as a task or a side project that go on between the two events. Network is a connection between the start and finish of the event. This approach represents a range of commonly used and referred to as arrows activity (Activity-on-Arrow, AOA) otherwise known as the node activity (Activity-on-Node, AON) Dummy and Events Network is an activity that has the gift of two starts and finish of an event Critical Path Analysis Analysis of the critical path or critical chain model is to find the shortest schedule for a series of activities. The definition of the critical path is the longest path through the network (Mortan, 1999). The main purpose of the critical path analysis was carried out to determine the quantity of the next (ES, LS, LF and S) for each of the following: ES EF LS LF Figure 1: Activities in the CPM network 38

6 Abdul Talib Bon & Nurul Haerani Mohamad Where: Early Start Time Activities (Early Start, ES)] Activity Start Date End (Late Start, LS) Start Date Completion Activities (Early Finisht, EF) Final Activity Completion Date (Late Finish, LF) Slack time / Slack (S) Sub critical path is a chain of activities that are not all dependent on the critical path. However, sub-critical path allows the activities carried out in a longer time than planned, but over time it must not exceed the amount of time in the critical path. Thus, the amounts of time during subcritical path to be calculate. The formula below use in important formulate the critical path: EF = ES + t (1) LF = LS + t (2) S = LS S = LF EF (3) With the above equation, the whole project or production processes can be analyzed to involve: i. Critical Path The chain of critical activity for the project or the manufacturing processes. It is the longest path and will cause delays throughout the project or the manufacturing process. ii. Time (T) The time to complete the project or the manufacturing processes by adding the expected time (t) to the critical path. iii. Variance (V) The variance to increase the variance of the critical path (v) in the critical path activity. Forward Pass is all activities must be completed before any activity can begin. It is a logical operation. Backward Pass was a late time activities without delay of any activity. It is a logical operation (Heizer, Render (2006). 3.5 Survey Instrument Interview Method Survey is a study using interviews and questionnaires as research instruments. Interview was conducted to obtain a true picture of the research problem. According to Chua (2006), the interview is defined as two-way conversation that aims to collect information on the study. Interview is a two-way conversation is conducted through a face interaction between interviewer and respondent. Interview method was used to collect information and data. The data were collected from interviews have been compiled systematically for data analysis, interviews can be conducted. In this study, researchers interviewed the production line operating managers in product manufacturing and keyboard operators 39

7 Jurnal KALAM Vol. 6, No. 1, Page working on the production line to learn more about the production processes of the keyboard and the problems faced by the production lines and factories Method of Observation Observation was done on the production line system. Information and data will be taken in the use, operation and production of the system layout. Records and inspection list will be considered. 4. Data Analysis 4.1 Introduction Information about data analysis was done as a result of collecting data based on interviews and observations conducted at the production line at an electronics factory produced keyboard. Next POM-QM for Windows (Version 3), Project Management (PERT / CPM) Module Software was used to analyze the data collected. The data analyzed were for the production and processing of any relationship between each of the production process at the factory keypad 4.2 Development Activity Scheduling Hence all the data obtained in the development of a schedule activity before being put into the software POM-QM for Windows (Version 3), Project Management (PERT / CPM) Module for analysis. Schedule of activities is aimed to generate employment to facilitate data analysis is made. The process of making keyboard in production lines involving 3 work station where the main work station 1 (Workstation 1) involves the installation of keyboards, workstations 2 (Workstation2) involves the keyboard and prints the work station 3 (Workstation3) all final checks on the keyboard to do. The combinations of these workstations represent the system in the process of making the keyboard the factory production line. Appendix A shows the process of producing the keyboard. 4.3 Data Analysis POM-QM for Windows (Version 3), Project Management (PERT / CPM) Module) Software The result of scheduling activities of keyboard production process in manufacturing production lines of the factory will further incorporated into the POM-QM for Windows (Version 3), Project Management (PERT / CPM) Module software for analysis. Table 2 shows the data need to be filled for decision analysis. 4.4 The Data Analysis Using POM-QM for Windows (Version 3), Project Management (PERT / CPM) Module Software Table 2 shows the result of the analysis keyboard production process in manufacturing production lines of the factory using the POM-QM for Windows (Version 3), Project Management (PERT / CPM) Module software. The results of the analysis show the results of activity Early Start Date (ES), Activity Start Date End (LS), Full Time Activities First (EF), Final Activity Completion Date (LF) and the slack time / Slack (S). 40

8 Abdul Talib Bon & Nurul Haerani Mohamad Table 1: The result of scheduling that has been developed. Table 2: Keyboard Production Process using POM-QM for Windows (Version 3), Project Management (PERT/CPM) Module Software 41

9 Jurnal KALAM Vol. 6, No. 1, Page Network Diagram F K A B C D E G I J L H M Q U T S P O 2 R V W Figure 2: Network Diagram of Keyboard Production Process Gantt Chart The results of analysis are also shown in the form of a Gantt chart. Figure 3, Figure 4 and Figure 5 shows the results analysis using the POM-QM for Windows (Version 3), Project Management (PERT / CPM) Module software. Based on all the Gantt chart below, the critical path for each task is shown clearly. Figure 3: Gantt chart (Early Times) 42

10 Abdul Talib Bon & Nurul Haerani Mohamad Figure 4: Gantt chart (Late Times) Figure 5: Gantt chart (Early and Late Times) 4.5 Determination of the Critical Path (Ctitical Path) In determining the critical path analysis, there are two methods used in the method of Forward Pass (Forward Pass) and Access to Back (Backward Pass). Computation of Forward Pass starts from node "start" to the node "end". At each node is calculated for the fastest time of the occurrence of the event. Backward Pass the computation begins with the calculation of node "end" node "start". The analysis by the method of determines the critical path using Forward Pass and Backward Pass. Referring to the analysis results, each task is available, it appears the critical path or critical path for the production of panel products in the key studies of factory production lines are A-B-C-D- E-F-G-H-I-J-K-L-M-N-O-P-Q-S-T-U-V-W, the critical path for the production of panel products in the key studies of factory production lines. All activities are located on the critical path activities - activities that should become priorities. 5. Conclusions and Recommendations Based on the results obtained, the researchers have put forward several proposals that are expected to assist entrepreneurs in improving the performance of manufacturing plants and in increasing productivity in the factory. 43

11 Jurnal KALAM Vol. 6, No. 1, Page Data Analysis Results Discussion In this section, the discussion of the analysis conducted studies in which data and information gathered through observations in the next production line testing. According to the results obtained from the software POM-QM for Windows (Version 3), Project Management (PERT / CPM) Module, the researcher found that there is indeed a disturbing critical path time line of production and affect the productivity of the fact. Table 3 and Figure 6 below shows a summary of the results of the analysis carried out for the product line in the factory production line in the study. Table 3 shows the total production time and the task which is within the critical path. Task that has slack is a critical task in which this task cannot be delayed. Refer to Table 3, R (Electrical Function) has no slack. Next referring to Figure 6, researchers found that the critical path or critical path for product manufacturing production process production manufacturing of keyboard studies at the factory production line is A-B-C-D-E-F-G-H-I-J-K-L-M-N-O-P-Q-S-T-U-V-W. All activities are located in critical path activities that should be given priority. In addition researchers have identified factors that can optimize the production of the keyboard so that the factory production line does not reach its maximum. Based on the Critical Path Method, GNP, critical pathways have been identified and are working to facilitate researchers to identify the problems that arise during the production process carried out the keyboard. Task R of Inspection Function (Electrical Function) are not included in the critical path identified as a key factor in optimizing the production. Here, researchers suggest to reduced activity of R task. In addition, the task Q is examining the finger pressing the activity has a relatively long (150 seconds) can also be reduced. TASK ACTIVITY DESCRIPTION Table 3 SLACK PERFORMANCE TIME (SECONDS) A Gear Link 39 / Alignment B Housing Alignment / 39 C Gear Link & Housing / 38 Assembly D Affixing Support Panel, Sup Panel / 15 & Membrane E Riveting Housing / 15 F Label Printing / 18 G Label Affixing / 18 Ws 1 44 H Greasing / 30 I Keytop Multikey Insertion / 68 J Keytop Mounting / 170 K L M Keytouch Check (By Finger) Keytouch Arrangement Printing Keyboard (Pad) / 40 / 35 / 120 Ws 2

12 Abdul Talib Bon & Nurul Haerani Mohamad N O P Q R S T U Heat Trough IR 32 / Machine Visual Check (Barcode / 93 Scanning) Keyboard Appearance (Barcode Input / 85 Scanning) Keytouch Inspection / 150 Function Check 20 (Electrical - Function) Bezel Assembly & Rivet Tightening / 20 Pad Sheet Assembly, Membrane / 20 Folded & Cover Tape Affixing Key Arrangement Check By / 25 Machine V Warpage Check / 20 Ws 3 W Packing / 12 TOTAL 1122 TASK ACTIVITY DESCRIPTION Table 4 PREDECESSORS PERFORMANCE TIME (SECONDS) 39 A Gear Link Alignment - B Housing Alignment A 39 Gear Link & C Housing B 38 Assembly Affixing Support 15 D Panel, Sup Panel C & Membrane E Riveting Housing D 15 F Label Printing E 18 G Label Affixing F 18 H Greasing G 30 I J K L M N Keytop Multikey Insertion Keytop Mounting Keytouch Check (By Finger) Keytouch Arrangement Printing Keyboard (Pad) Heat Trough IR Machine E,F,H 68 I 170 J 40 J,K 35 J,L 120 M 32 Ws 1 Ws 2 45

13 Jurnal KALAM Vol. 6, No. 1, Page Visual Check 93 O (Barcode Scanning) N P Keyboard Appearance (Barcode Input O 85 Scanning) Q Keytouch Inspection P 150 Function Check 20 R (Electrical Function) P S Bezel Assembly & Rivet Q,R 20 Tightening T Pad Sheet Assembly, Membrane S 20 Folded & Cover Tape Affixing U Key Arrangement Check By T 25 Machine V Warpage Check U 20 W Packing V 12 TOTAL 1122 Ws Recommendations In this section, recommendations are divided into two parts. The first part is about a proposal to improve the performance of production lines. The proposed improvement of production line systems produced. While the second part, some of suggestions submitted to the next researcher Recommendations to Production Line To overcome this problem, the appropriate step is to optimize the activity and task R, Q. Time task activity can be optimized by increasing the R inspection system more efficient and more high tech. Time of inspection activities of task Q is pressing the fingers can also be optimized. This can be done by manual inspection of the fingers was replaced with a provision of the inspection machine has a keyboard inspection system more efficient. In addition, the quantity of charge carriers in the task Q can also be strengthened to check the keyboard can be optimized Recommendations to the future research Based on interview and observation made during this study, some of suggestion regarding optimization of the automated production chain has been provided. Among the suggestions for further research are: i. Review and recommend optimization of production chains based on the Assembly Line Balancing. Assembly Line Balancing is one of the easier ways to optimize the production line by reducing the number of workstations (workstations). ii. Methods of data collection more accurate and efficient. Researchers then have to get more accurate data and appropriate to reduce failure rates and defects in the process of data collection. 46

14 Abdul Talib Bon & Nurul Haerani Mohamad Figure 6: (Critical Path) A-B-C-D-E-F-G-H-I-J-K-L-M-N-O-P-Q-S-T-U-V-W for keyboard production process 47

15 Jurnal KALAM Vol. 6, No. 1, Page Limitation of study There is a limitation of the study are faced during this study. Software POM-QM for Windows (Version 3) has certain limitations in the data input. Because software POM-QM for Windows (Version 3), Project Management is the student version, there are limitations that restrict the use of software only to some task, the activity and some other elements. Therefore, data analysis using POM-QM for Windows (Version 3), Project Management (PERT / CPM) Module will be produced to have a little difference in output when compared with the actual process. 5.4 Conclusion There is a limitation of the study are faced during this study. Software POM-QM for Windows (Version 3) has certain limitations in the data input. Because software POM-QM for Windows (Version 3), Project Management is the student version, there are limitations that restrict the use of software only to some task, the activity and some other elements. Therefore, data analysis using POM-QM for Windows (Version 3), Project Management (PERT / CPM) Module will be produced to have a little difference in output when compared with the actual process. References Amaratunga D, dan Baldry D. (2003). A Conceptual Framework to Measure Facilities Management Performance. Journal of Facility Vol.21 No.2,pp Chua Patrick Hui and Sau Fun Frency Ng (2006). A study of The Effect of Time H. Chang, S. S. Sapatnekar (2003). Statistical timing analysis considering spatial correlations using a single PERT-like Traversal. IEEE ICCAD, November 2003, Heizer, Jay and Barry Render (1996). Production & Operation Management. 4 th ed, Massachusetts : Ally Bacon, 1996, pg Hitomi, K. (1994). Automasi Concept And a Short History. Technovation. 14. Jay Heizer & Barry Render (2006). Operations Management. 8 th ed. Pearson International Edition. Jordan, S. (1996). Man and Machine in Harmony. Assembly Automation. 16. Luke, H.D. (1972). Automation for Productivity. USA: John Wiley and Sons,Inc. Moder, J.J., Project management with CPM, PERT and Precedence Diagramming. 3 rd Reinhold: New York). edition, 1983 (Van Nostrand Morton, Thomas E. and David W. Pentico Heuristic Scheduling Systems with Applications to Production Systems and Project Management. New York, New York: John Wiley & Sons, Incorporated. Paul D. Ericksen, Nathan J. Stoflet & Rajan Suri (2007). Manufacturing Critical-path Time (MCT): The QRM Metric for Lead Time. April Peter Stelth & Guy Le Roy (2009). Projects Analysis through CPM (Critical Path Method).School of Doctoral Studies (European Union) Journal, No.1, July Ron Davis (2001). Total Productive Maintenance Overview. The annals of Dunarea De Jos University of Galati Fascicle V, Technologies in Machine Building, ISSN Terwiesch, C. and Bohn, R.E (2001), Learning and process improvement during production ramp-up, International Journal of Production Economics, Vol. 70, ms Terry Hill (1991). Production & Operation Management: Text & Cases, Prentice Hall, 1991, ms Thomas E. Morton (1999). Production Operation Management. Carnegie Mellon University. 48

16 Abdul Talib Bon & Nurul Haerani Mohamad Vandevelde, A. and Van Dierdonck, R. (2003), Managing the designmanufacturing interface, International Journal of Operations & Production Management, Vol.23 No.11, pp Woolf, Murray B. Faster (2007). Construction Projects with CPM Scheduling(M). McGraw Hill, Wu Yi, Qiu Wanhua, Zhou Peng & Lin Jian (2009). Project Delay Risk Analysis in Aviation Manufacturing Entreprise Journal of Engineering Industry. Vol.5 No. 2, X. G. Huang, Y.S. Wong, Z.J. Liu & Z.M Qiu (2005). Critical-path-analysis-based dynamic component supplier optimization. International Journal of Computer Integrated Manufacturing, Vol. 18, No. 8, December 2005, Yaping Zhan, Andrzej J. Strojwas, Mahesh Sharma, David Newmark (2005). Statistical Critical Path Analysis Considering Correlations. 49