Faculty of Engineering, Environment and Computing 356EM Manufacturing Process Improvement


Faculty of Engineering, Environment and Computing

356EM Manufacturing Process Improvement


Deferral/Resit Assignment Brief _July 2021


Module Title

Manufacturing Process Improvement





Module Code


Coursework Title (e.g. CWK1)

Deferral/Resit Coursework

Hand out date:



Adriana Ortiz

Due date and time:


05/07/2021 by 18:00:00

Estimated Time (hrs):


Word Limit*:2500




Coursework type:


% of Module Mark/



Submission arrangement online via Aula:

File types and method of recording: Word/Excel


Mark and Feedback  method electronic via Aula


Module Learning Outcomes Assessed:


LO1- Differentiate between tiers of the Quality Hierarchy and design quality improvement programmes to transcend the hierarchy in order to contribute to increasing business performance.

LO2- Appraise different quality improvement techniques which are applied in a manufacturing environment.

LO3- Critically review the main approaches to achieving lean manufacturing systems.

LO4- Apply a manufacturing systems engineering design/redesign methodology to design flow lines and cells.





Flex Furniture Ltd (FF Ltd) manufactures a wide range of upholstered furniture for a range of retailers across the UK.  FF Ltd is in the process of refining the production of the high demand type of product, the three seater sofa.


Production Processes

The three seater sofa is made up of two variants Fabric (TSF) and Leather (TSL).  The two variations start from station 1 (Operation No 1) and have a common process route.


Flex Furniture Ltd  is currently producing to mass production principles. The machines have a functional layout and produce parts in large batches. All moves within the same section are done manually, using trolleys.


The key manufacturing processes include sawing, CNC machining, spot welding, turning (lathe 2), assembly (1st and finally), and packing.



Customer Requirements

·        6,000Three seater sofas per month.

·        Products are deliver every day to the customer by lorry.

Work Time

·        20 working days in a month

·        Operating a 1 shift system in all production operations

·        7 hours per day excluding breaks

Production Control information

Receives a 30 day forecast from the Local Retailer and enters it into the MRP system

Issues a 5-week forecast to Range Materials (RM) Ltd (Supplier).

Secures raw material by weekly faxed order release to RM Ltd who deliver every Mondays and Wednesdays

Receives daily call off from  Ltd

Generates weekly MRP schedules for each department

Issues a daily shipping requirement to dispatch section



The processes to produce the three seater occur in the following order:


Operation No Op. 1 Op.2 Op.3 Op.4 Op.5 Op.6 Op.7
Operation type Material Cutting Cover Packing Sewing Foam cutting Frame Assembly Upholstery Packing
Process time/ unit (sec) 40 30 Manual 60

Automatic 30


20 25 40 15
Changeover time (min) 0 95 10 0 45 0 0
Uptime 100% 78% 100%  100% 82% 82% 82%
Rejects   7%     20% 12% 12%



WIP (Inventory)


–         Pre Material Cutting : 5 days

–         Post Material Cutting:   600 F

250 L

–         Post Cover Packing:     1100 F

300 L

–         Post Sawing:                    250 F

160 L

–         Post Foam cutting:       1200 F


–         Post Frame assembly:      80 F

75 L

–         Post Upholster:                  40 F

50 L

–         Post packing:                    750 F

250 L

Using the information provided an answer to the following questions.





1.      Draw a value stream map to represent the current state with timeline of the manufacturing process of the three seater sofa.

(15 marks)

2.      Calculate the Takt time, lead-time, and VA ratio. Comment on the results and any implications that the current state has on meeting customer requirements.

(15 marks)

3.      Using the information provided identify problem areas and critically appraise the current state.

(25 marks)


4.      The Critical analysis of the Flex Furniture Ltd production line indicate that there is a low quality pass rate on the Frame Assembly process (80% pass rate).  The company decided to do an analysis of the causes of these failures in order to identify and improve the failure that occurs more frequent and carries more costs. Data was record for the following six failure modes:

N. Failure Mode Causes N. of Failures
1 Defective inner part 120
2 Inappropriate frame dimension 63
3 Incorrect sealing 255
4 Poor quality of raw material 20
5 Incorrect parts 85
6 Misalignment of parts 300


In addition, the production manager has also provided you with the repair cost involved for each type of failure as it is illustrated in the following table.

N. Failure Type Cost (£)
1 Defective inner part 15
2 Inappropriate frame dimension 65
3 Incorrect sealing 8
4 Poor quality of raw material 4
5 Incorrect parts 22
6 Misalignment of parts 30


Using the information above, perform a Pareto analysis to identify the three critical failures or defects to prioritize the improvements actions that will show a bigger impact on cost reduction. Justified and explain your answer.

(20 marks)


5.      Evaluate the possibility of using cells design in the processes the manufacturing process of the three seater sofa. Indicate how many cells would you use and justify your answer.




1.      You are expected to use the Coventry University APA 7th Edition referencing format. For support and advice on this students can contact Academic Liaison Librarian or Centre for Academic Writing (CAW).

2.      Please notify your registry course support team and module leader for disability support.

3.      Any student requiring an extension or deferral should follow the university process.

4.      The University cannot take responsibility for any coursework lost or corrupted on disks, laptops or personal computer. Students should therefore regularly back-up any work and are advised to save it on the University system.


The marks will be awarded for detailed, accurate explanations and comments along with completeness of charts.



Any suspected cases of plagiarism or collusion will be dealt with via Coventry University disciplinary procedures.

Do not “cut and paste” paragraphs/chapters from sources of literature.

All quotes, figures, illustrations etc must be correctly referenced via the Coventry Harvard referencing system.


Marking Rubric







Innovative response, answers the question fully, addressing the learning objectives of the assessment task.  Evidence of critical analysis, synthesis and evaluation.


  A clear, consistent in-depth critical and evaluative argument, displaying the ability to develop original ideas from a range of sources.  Engagement with theoretical and conceptual analysis.


  Wide range of appropriately supporting evidence provided, going beyond the recommended texts.  Correctly referenced.   An outstanding, well-structured and appropriately referenced answer, demonstrating a high degree of understanding and critical analytic skills.  
Upper Second






A very good attempt to address the objectives of the assessment task with an emphasis on those elements requiring critical review.   A generally clear line of critical and evaluative argument is presented.  Relationships between statements and sections are easy to follow, and there is a sound, coherent structure.   A very good range of relevant sources is used in a largely consistent way as supporting evidence.  There is use of some sources beyond recommended texts.  Correctly referenced in the main.   The answer demonstrates a very good understanding of theories, concepts and issues, with evidence of reading beyond the recommended minimum.  Well organised and clearly written.  
Lower Second





Competently addresses objectives, but may contain errors or omissions and critical discussion of issues may be superficial or limited in places.



  Some critical discussion, but the argument is not always convincing, and the work is descriptive in places, with over-reliance on the work of others.


  A range of relevant sources is used, but the critical evaluation aspect is not fully presented.  There is limited use of sources beyond the standard recommended materials.  Referencing is not always correctly presented.


  The answer demonstrates a good understanding of some relevant        theories, concepts and issues, but there are some errors and irrelevant material included.  The structure lacks clarity.  






Addresses most objectives of the assessment task, with some notable omissions.  The structure is unclear in parts, and there is limited analysis.   The work is descriptive with minimal critical discussion and limited theoretical engagement.   A limited range of relevant sources used without appropriate presentation as supporting or conflicting evidence coupled with very limited critical analysis. Referencing has some errors.   Some understanding is demonstrated but is incomplete, and there is evidence of limited research on the topic. Poor structure and presentation, with few and/or poorly presented references.  



Some deviation from the objectives of the assessment task.  May not consistently address the assignment brief.  At the lower end fails to answer the question set or address the learning outcomes.  There is minimal evidence of analysis or evaluation.   Descriptive with no evidence of theoretical engagement, critical discussion or theoretical engagement.  At the lower end displays a minimal level of understanding.   Very limited use and application of relevant sources as supporting evidence.  At the lower end demonstrates a lack of real understanding.  Poor presentation of references.   Whilst some relevant material is present, the level of understanding is poor with limited evidence of wider reading. Poor structure and poor presentation, including referencing. At the lower end there is evidence of a lack of comprehension, resulting in an assignment that is well below the required standard.


Late submission


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