Equipment Efficiency: Performance and Motion study Operations Analysis and Improvement 2009 Spring Dr. Tai-Yue Wang Industrial and Information Management Department National Cheng Kung University

Presentation We will examine the second equipment efficiency indicator based on two factors: Losses due to minor stoppages (usually not registered). Reduction caused by the components deterioration/wear.

Presentation Responsible these machine stoppages. Small breakdowns or device (fixture and tooling) holdups Improper adjustment or interaction between the worker and the machine cycle. Time and motion study allows us to optimize the relationship between the worker and the machine. Investigate the worker to tending more than one machine. Worker-machine and the machine-machine diagrams.

Introduction - Methods Improvement Also known as time and motion study. Methodology whose goal is to decrease the amount of work (shorter cycle time) by improving the existing work methods and layout. 20 16 12 11 9 7 14 5 4 8 15 13 10 19 18 17 6 1 2 3

Introduction - Methods Improvement Idle times are decreased or eliminated. Those non-productive activity times are eliminated from the process. If it is applied to the machine setup process, it could be consider as a SMED tool. Is included in the 20 keys as key number 6. Improves the overall performance of the equipment efficiency ratio.

Introduction – Methods Improvement Time study is one of the first steps in a motion study. Quantify the current standard as well as to document achieved time savings Alternate procedures (methods) are proposed. At first, may seem worse than the current method. Lack of familiarity and the change resistance of workers. Example of animal behavior.

Introduction. Motion Study The importance of eliminating minor stoppages depends on the process. cycle time -> 2 minutes A 3 second reduction in a day of 24 working hours would result in the production of 18 more parts. Elimination of minor production stoppages. Kikuo Suehiro -> methodologies for minor stoppages elimination.

工作研究 工作研究包含「方法研究」與「時間研究」兩部分 「方法研究」就其考慮整體或細部之不同著眼點，可分為程序分析(process analysis)及動作分析(motion analysis)等。

程序分析 在進行程序分析前，要先了解何謂「工作程序」。 所謂工作程序，乃是完成一項工作所需經過的全部操作與路線。 程序分析是以系統化的分析方法，將整個工作方法加以分析與研究，以發揮整體效率，而非針對方法中已發生危險或困難的部分加以修正與解決而已。

程序分析--分析的工具 柏拉圖 義大利經濟學家柏拉圖(Pareto)研發了柏拉圖分析(Pareto analysis)工具來說明財富集中分佈情況，而柏拉圖分析也可以利用來制定問題的範圍。 魚骨圖 甘特圖 PERT圖

程序分析的實施步驟 1/7 程序分析前，應先有流程圖 選擇 記錄 分析 建立 施行 查考

程序分析的實施步驟 2/7 選擇 選擇之考慮因素如下： 經濟的考慮 技術的考慮 人的反應

程序分析的實施步驟 3/7 紀錄 圖表 程序圖(process chart)為程序分析之最主要工作，其用於將作業過程記錄下來。 符號 ○：操作 ：搬運 □：檢驗 D：遲延 ▽：儲存

程序分析的實施步驟 4/7 分析 分析事項 因程序圖以操作(○)、搬運()、檢驗(□)、遲延(D)、儲存(▽)等五種事項進行記錄，分析時即可從此五種事項進行之。 操作分析 搬運分析 檢驗分析 儲存分析 遲延分析

程序分析的實施步驟 5/7 分析時應注意的事項 開放式的思考 不要盲目地忙碌 儘量利用分析模式，以尋找出分析的結果

程序分析的實施步驟 6/7 建立 剔除 合併 重排 簡化

程序分析的實施步驟 7/7 施行 施行的三大要點 保證確實施行 提出建議書 建議須於最適當的時機提出。 各有關人員均須給予告知及說服。 均須給予訓練及教導。 保證確實施行 提出建議書

程序分析的結果

程序分析的結果

動作分析(1/4) 一般常使用之方法有下列三種： 目視動作分析(visual motion study) 動素分析(therblig analysis) 影片分析(film analysis)

動作分析 2/4 動素之分類 依其操作特性可將其區分為四類： 實體性(physical)之動素 目標性(objective) 心智或半心智性(mental or semi-mental) 遲延性

動作分析 3/4 「動素」的定義、起點、分析與改善 善用「動素」以改善動作，吾人須更深一層的瞭解「動素」的具體定義、起點與終點之特性與表徵，與其之分析與改善方向。茲詳述如下：

動作分析 4/4

Motion economy principles Frank and Lillian Gilbreth. They defined the operation standard time by listing and measuring working elements. They divided it in small tasks called Therbligs They regrouped and optimized these small tasks to form the complete operation in various ways.

Motion economy principles The principles of motion economy are the result of their diligent work. These principles are still used. Frank was able to out perform younger bricklayers. These principles are simple rules that facilitate the proper design of operations.

Motion economy principles Example: Better symmetrical movements. The drawing of the left represents a non efficient process.

Motion economy principles Example: Better to split the weight. The drawing of the left represents a non efficient process.

Motion economy principles Example: Sitting down is better. The drawing of the left represents a non efficient process.

Motion economy principles Example: Manually control It is recommended to use analog displays with properly noted performance zones rather than digital ones.

Motion economy principles Other examples Efficient use of other displays. It is recommended, for example, lateral movements instead of up-down movements. Principles of motion economy vs. best working conditions to increase productivity. Some studies have demonstrated that productivity increases when working under poor lighting conditions. Negative consequences on the worker motivation.

Motion economy principles The human body has been analyzed and optimum work distances and work envelopes have been defined. Arms sweeping area have been fixed when the worker is seated or standing.

Motion economy principles Proper bookcase heights for storage are also known. Accidents can be avoided or reduced. The hands can be let free by using feet to perform certain tasks

動作經濟原則 1/6 動作經濟之意義 動作經濟原則之目的在於減少操作者之疲勞，並縮短操作時間，亦即使操作者在最經濟有效的條件下進行工作，以增進工作效率。

動作經濟原則 1/6 動作經濟之類別 歸納成下列三大類：(1)與人體動作之運作有關之動作經濟原則。(2)與工作場所之佈置及工作環境條件有關的動作經濟原則。

動作經濟原則 2/6 與人體動作之運作有關之動作經濟原則 雙手應同時開始，並同時完成動作，除規定休息時間外雙手不應同時空閒。 雙手動作應對稱，方向應相反，並應同時完成。 實施手動作應儘量採用較低等級之動作種類。 多利用最強有力的姆指和中指。 握持工具時宜使用靠近手掌之手指部分。 實施扭轉動作，須將臂肘彎曲。

動作經濟原則 3/6 應儘量利用物體之運動量，但如需使用肌肉力量制止時，則應將其減至最小限度。 連續之曲線運動，較優於突然改變方向之直線運動。 如工作能由腳操作時，應設法安排使其與手合併 行動。 操作員若站立來操作足踏機構，其效果不佳。

動作經濟原則 4/6 與工作場所佈置及工作環境條件有關的動作經濟原則 原則計有下列八條分述如下： 需使用之材料與工具應置於固定位置，並依最佳的操作順序排列，以消除或減少尋找與選擇兩動素。 應用重力櫃櫥與墮送方法，以求減少伸手和移物所需的時間。 物料與工具均置於垂直與水平之正常工作面積內。

動作經濟原則 5/6 應設置可以調整高度的舒適座椅，使操作時坐姿適宜，而提升工作效率。 應設置良好通風、照明、溫度等適合於操作的工作環境。 考慮工作場所之視覺需求，儘量減少眼睛凝視的 時間。 節奏般的動作可使操作流利，故儘量將動作安排成符合輕鬆與自然的韻律。 工具與物料之放置地點，應依動素發生之最佳順序 排列。

動作經濟原則 6/6 與工具和設備設計有關的動作經濟原則 動作經濟原則有四項 儘量將兩種或兩種以上的工具合併為一。 儘量使用夾具，持住待加工物於一指定位置。 槓桿、手柄、轉輪等各種控制設備之裝配與設計應使其具備最高之機械利益為原則，並應放置在操作員的近處，以利控管。 儘量使用動力工具或半自動工具。

Value analysis Focuses on worker movements and workplace layout. Several production tasks can be redesigned and improved. Some companies have an ergonomics department.

Value analysis - Examples The only difference in the two activities is the location of the stop valve. Worker efficiency can be significantly improved.

Value analysis - Examples Reduce the effort required by a worker if an electric or pneumatic host is installed. The number of times that this task is carried out during the day, makes this process very harmful for the worker.

5W2H and 5-W methods The “5W2H” tool is very simple and consist on asking a group of questions about the task that is been analyzed.

5W2H and 5-W methods The response to change is about the same. Workers seldom see the necessity to think about another method for carrying out a task. This technique facilitates the analysis of operations that do not add value to the process. Some of the solutions seem trivial.

5W2H and 5-W methods “the 5-W" method. Consists of asking “Why?” 5 times in order to find the root of the problem. Differentiate the symptoms that produces the problem from the real causes of the problem.

Worker-machine diagram Direct observation or the use of a camcorder is adequate to document the problem for analysis. Analyze a very fast or a very slow operation. Special camcorders.

Worker-machine diagram Use production cycle analysis in which the machine and the worker interact with each other. Operation should be divided in short but measurable tasks. Separating the machine and the worker tasks.

Worker-machine diagram Worker-machine diagrams can facilitate this work. These diagrams represent the task sequence that the worker carries out when interacting with the machine.

Worker-machine diagrams These diagrams are used to analyze idle time and are considered an important improvement tool.

Worker-machine diagrams The analyst is able to optimize the working cycle. The machine idle time decreases.

Machine-worker ratio If the machine task duration is very long, the worker could operate more than one machine. The right number of machines controlled by each worker is determined through the machine-worker ratio.

Machine-worker ratio Machine and worker cycle time -> All those operations where the resource is operating or occupied are considered. Even those shared with the worker.

Machine-worker ratio The value of the ratio determines two possible situations for the right number of machines. If the ratio is 7.6, the worker should be able to handle 7 or potentially even 8 machines. Machine-worker ratio must be studied in this steady cycle.

Machine-worker ratio Next figure will show the temporary evolution until achieving a steady cycle. In the case where the worker handles two machines. The working cycle is fixed by the machine. When the worker handles three machines. The working cycle is fixed by the worker.

Machine-worker ratio

Machine-machine diagram One-piece-flow strategy pointed out the importance of achieving the ideal flow between working centers. The relationship between machines’ operations involved in the manufacturing process should be studied.

Machine-machine diagram Similar to the worker-machine diagram. Analyze the product flow and the idle time in one working cycle when two or more machines are related. Draw the diagram. Steady cycle. Start with the machine which fixes the working cycle. This machine does not have idle time.

Summary In this chapter some tools to facilitate the motion study in a company have been presented. The studied worker-machine and machine-machine diagrams facilitate the identification of idle time in working cycles. Thanks to the presented improvement methodologies it is possible to eliminate those idle times. Therefore, the performance rate (included in the OEE ratio) increases.