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Read the five flow indicators of R & D efficiency insight
2022-07-23 20:36:00 【JackieZhengChina】
author | Zhang Le
Catalog
1 Digital age , Software development itself should also be digitalized
2 Flow framework and five flow indicators
3 Common bottlenecks and solutions in the R & D process
1. Scarce experts or resources , Cause the flow to be blocked
2. Lack of automation or backward engineering ability , It leads to inefficiency
3. A tedious process , Lead to waiting and long time consuming
4. Too much dependence , Cause work flow to stop
1 Digital age , Software development itself should also be digitalized
Have you felt , We are already at a critical juncture in the digital age .
Here's an interesting question first : The code scale in an ordinary car , With the code size of desktop operating system , Which is bigger ?
Maybe you have guessed the answer .
Many years ago , There are probably only 100 Ten thousand lines of code , For basic drive function ( Such as traction control ); It soon grew to 1000 Wan line code , To meet more and more digitalization 、 The growth of electronic control units , And the complexity of additional control software brought by electric vehicles ; With the development of automobile interconnection and information entertainment , In a few years ago , A BMW has reached 1 One hundred million lines of code ; With the popularization of automatic driving technology , Maybe soon there will be 10 One hundred million lines of code . by comparison , How much code is there in the operating system installed on our desktop computer ? Data shows , Microsoft Windows The operating system probably has 6000 About ten thousand lines of code .
therefore , Cars have become computers on wheels .

chart 1: Modern cars have become computers on wheels
This is just a small example , What I want to say is , We really , Has been in the key node of the digital era .
But a little ironic , In the digital age , As IT practitioners , Our R & D management , Sometimes it is still in a relatively backward state .
Many enterprises are still using the methods used in the last technological revolution , It continues the old behavior and outdated way of thinking . For example, use the method of measuring physical workers nearly a century ago , Pay too much attention to the length of work 、 Human resource saturation , Excessive demand for standardization and uniformity of work activities ; Pay too much attention to the proxy indicators of work output ( How many lines of code did the developer write 、 How much does the tester measure Bug), Instead of maximizing business results ; Pay too much attention to local optimization ( The degree of automation of a certain research and development process 、 What is used DevOps Tools ), Not global optimization ( End to end delivery efficiency and quality )......
So that now , In many cases, the software development process is still a black box , Lack of end-to-end visibility , Where is the congestion 、 Where is waste 、 Where there are risks , Managers may not know , product 、 Development 、 test 、 The real pain points of operation and maintenance , It is also easy to be buried in endless needs and work , It's even scarier , After a long time, everyone is used to it .
however , We still have something to pursue , We need to find a way , Let software research and development itself be digitalized . Digitalization is from the physical world , Mining data , Rough out information , Refine knowledge , Gather wisdom , Ultimately improve productivity .
According to this logic , R & D digitalization , We can start with building an effective R & D efficiency insight system .
The topic of R & D effectiveness insight system is very big , It involves the construction of R & D infrastructure 、 Design of measurement index system 、 Construction of insight analysis model 、 Insight into the realization of tool products 、 Operation based on data-driven and experimental thinking . Limited to space , This article only expands a small part , That is, focus on the five flow indicators in the value stream management method of software delivery , Effective insight into the R & D process , And analyze the potential problems and bottlenecks .

chart 2: R & D efficiency insight system
2 Flow framework and five flow indicators
stay 2018 At the end of the year, there is a book named 《Project to Product: How to Survive and Thrive in the Age of Digital Disruption with the Flow Framework》 Publication of works , The book points out that business is related to IT The disconnect between is one of the fundamental reasons for the failure of digital transformation , And further refined a called “ Flow framework ” New model of , It is used to establish the missing connection between business driven digital transformation and the technological transformation supporting them .
I remember that it was Mr. He Mian who recommended this book to me , After I saw it, I really felt sorry to meet you late , I think the contents of the book have strong guiding significance and high reference value for the whole industry , Then I decided to translate it into Chinese with my friends ( Forthcoming publication , Coming soon ).
In this paper, we will first focus on the five flow indicators in the flow framework .

chart 3: Five liquidity indicators
You may want to ask , Why is it called “ flow ” Index ?
This is because , Lean thinking is the bottom logic of flow framework and its related flow index design , As the five principles of lean thinking emphasize , We should accurately define value according to specific products 、 Define value streams for each product 、 Make value flow continuously 、 Let customers pull value from manufacturers , And the pursuit of perfection .
therefore , Based on lean thinking , Liquidity indicators measure the flow of value , They collectively indicate the efficiency and health of an organization in the process of delivering value . There are five liquidity indicators , They are the flow rate 、 Flow time 、 Flowing load 、 Flow efficiency and flow distribution . Make comprehensive use of these five indicators , We can tell a complete story about the value stream of software development , Answer the essential question about the efficiency of R & D delivery .
1. Flow rate

chart 4: Flow rate
Index definition :
Flow items completed in a given time ( Such demand 、 Defects or other types of work ) The number of , The flow rate can be used to measure productivity .
How to use :
Track the flow rate , To effectively evaluate and predict how much work the team can deliver . When the flow rate is too low , The cause needs to be investigated in time , There may be a shortage of resources 、 Problems such as architecture or infrastructure , There may also be a flow stagnation caused by a large number of waiting .
Interpretation of indicators
The value increases :
It generally indicates that value delivery is accelerating
The value decreases , And the flow time is very long :
It generally indicates that delivery is blocked 、 rely on , Or work switching waste caused by too many WIPs
common problem
What is the difference between the concept of flow rate and agile rate ?
Flow rate is adapted from agile rate concept , The latter indicates that the team is in a period of time ( for example , Two week iteration ) How many work units have been delivered ( for example , Story points ). But the flow rate is the number of flow items completed in a given time , Suppose a version is completed 10 Needs and 5 A flaw , Then the flow rate of this version is 15. therefore , The key difference here is , The flow rate is simpler , It does not depend on the amount of work 、 An estimate of the scope or priority of each flow item .
Why is the flow rate calculated according to the number of demands , Not by story point ?
indeed , The size of current items may vary greatly , This will make people tend to use “ Story point ” or “T T-shirt ” Estimate .
however , Using the estimation of story points will easily lead to scale impulse ( Artificially estimate more ), On the contrary, it may be more inaccurate , It often leads to business / The game of numbers between products and R & D teams .
therefore , The flow rate tends to use the number of flow items ( Not the story point ) To estimate , According to the law of large numbers ( If there are enough tests or examples , The probability of an event is equal ), If there are enough current items , Then in a period of time, all current items are large , In another time period, all current items are very small , It should rarely appear .
in addition , Reasonable splitting of work items ( Such as decomposing requirements into business requirements - Product needs - Technical tasks ), To a certain extent, it will also reduce the impact of the difference in demand granularity on the accuracy of the index standard . If I'm not sure , While measuring the flow rate index , You can also scale the demand ( Such as development + The amount of testing ) Observe together as an auxiliary reference index .
The other thing to note is that , The measurement of flow rate is more suitable for tracking productivity and delivery trends within a value stream , Instead of comparing across value streams .
2. Flow time

chart 5: Flow time
Index definition :
From the current item is accepted and enters the value stream , The time it takes until it is completed , It includes the time when the work is active and the time when it is waiting .
How to use :
Track flow time , Make the delivery time more predictable through probability thinking , And answer a core question relatively accurately :“ When can the work be finished ?”. According to the research , Lead time indicators generally conform to Weber distribution (Weibull Distribution), So it is recommended to use 85% quantile ( Not the average ) To measure and predict the flow time .
Interpretation of indicators
The value is very low :
We certainly hope that the flow time will continue to be shortened . But when you see this value is very low , Don't be happy too soon , See if the work is accurately tracked . For example, in our actual work , Often appear “ make amends ” Demand situation , For example, when the development is completed and it is time to go online , Because the online order needs to be associated with a demand order , At this time, add a demand to the Kanban , Then drag directly from the first stage to the last stage . Similar situations will lead to the distortion of indicators , The accuracy of indicators is the foundation of measurement , We need extra attention . In the process of practice , We often observe the main indicators ( Such as flow time ) At the same time , Add an auxiliary reference index about data health ( Such as the proportion of abnormal data ), To ensure the confidence of the main index .
The value is very high , And the flow rate is very low :
It may be the work switching caused by too many WIPs , Or work is blocked , There is a lot of waiting time , Let the flow time be prolonged . We can combine the following flow load and flow efficiency to conduct a more detailed analysis .
common problem
Lead time 、 Cycle time 、 What's the difference between flow time ?

chart 6: Flow time vs Lead time
In lean production , There are two key indicators for process improvement , Namely “ Lead time ” and “ Cycle time ”. Lead time focuses on measuring the time of the whole process ( Work from “ newly build ” The state begins to “ complete ” Time difference between States ), Cycle time focuses on the time it takes to complete a step in the process ( Such as “ Development ” Cycle time of the phase ). The lead time can tell us the time spent in running the end-to-end process , Cycle time can help identify bottlenecks ( The step with the longest cycle time is usually the bottleneck ).
But to avoid confusion , The flow framework uses the name “ Flow time ” New indicators of . Flow time begins when work is explicitly accepted ( For example, the new requirements review passed and entered the scheduling ) Or implicitly accept ( For example, events that are automatically upgraded ) The moment of , This is completely different from the lead time when the work is put forward . The flow time can be used as an observation index of the delivery efficiency of the product R & D team , That is, the time from determining to do a certain work to completing ; The lead time is more observed from the perspective of the demand side , That is, the time required from the request to completion .
Why not use DevOps The change lead time commonly used in the community ?
From year to year DevOps Global survey report and DevOps In the community , Often use the name “ Change lead time ” The measurement of , English is Lead time for changes, That is, the lead time from code submission to deployment . Although we often use this indicator for efficiency measurement and analysis , But it has not been adopted by the flow framework .

chart 7: Change lead time change
Lead time is more a developer centric perspective , Instead of designing from a customer-centric or value stream centric perspective , So it is not enough to encapsulate business value , Although it is one of the important indicators of team engineering ability , But in essence, it is more partial 、 More procedural indicators . And the vision of flowing time is broader , What we observe is the end-to-end flow of work items in the software delivery pipeline , Is more partial to the overall situation 、 More consequential indicators .
Is the flow time calculated according to natural days or working days ?
As mentioned above , Flow time is a customer-centered design indicator , So it is based on “ natural ” Time, not “ Working day ” To calculate and measure .
3. Flowing load

chart 8: Flowing load
Index definition :
The number of work in process in the value stream ( Started 、 Hang in the air , That is, the work in progress ), Contains the number of flow items with active or waiting status .
How to use :
Current load is a leading indicator , It can be used to find the impact of too much WIP on speed indicators and team satisfaction . We can adjust and experiment constantly , Find the optimal flow load of the product value stream , At this time, the flow rate is high , And the flow time is short . The floating load can make the production research team better cooperate with the business demander , Find a balance between demand and capacity .
Interpretation of indicators
The value is low :
There may be only a small amount of work being done , There may be idle .
Higher value :
Excessive flowing load ( In the products ) It is likely to cause delivery delay 、 Cost increase 、 Quality decline 、 Employees complain , Arranging work beyond the capacity of the team for a long time will lead to job burnout . It can be further decomposed into the following two cases .
Higher value , And the flow time is very short :
There may be a lot of work neglected or shelved , There are many “ Zombies need ”, Has been stuck in the delivery pipeline, but because of the priority, there has been no time to deal with . At this time, it is necessary to clean up WIP , Evaluate what really needs to be done . If it is really important, let the work continue to advance in time , If it's not important, just move the work out of the delivery pipeline .
Higher value , And the flow time is very long :
Work switching caused by too many WIPs may be the culprit , Excessive flow load directly affects the delivery efficiency . At this time, lean practice can be adopted , Limit WIP and adopt pull model ( Such as using lean Kanban ). It may also be the role of insufficient resources / Increase capacity of Posts , Or improve the level of Automation .

chart 9: Flow time prediction based on little's law
One thing in particular to note , According to little's law , Flow time = Flowing load / Flow rate , When the current value of the current load is higher than ( Flow rate * Flow time ) The predicted value of , It indicates that there will be work that cannot be completed on schedule in the future . At this time, the risks of future delivery plans and cycles have been found , The prediction of flow time needs to be corrected , To achieve more accurate commitments / Decision making , This is the value of leading indicators .
common problem
Where should the current load be calculated ? Do you want to calculate the work that has not yet started ?
If you think of the value stream as a pipeline , All the flow items that have not been started or completed are at both ends of the pipe , The flow load is the number of work units in progress in the pipeline , Include all partially completed current items . When the flow load is too large , Because the queue time is too long , The overutilization of value stream will greatly affect the delivery speed .
Is there an absolute figure for the current load to indicate whether it is good or bad ?
It is difficult for the industry to have an absolute figure to explain the current load , Different business types 、 Teams at different stages of development , There are great differences in the bearing capacity of flowing load . therefore , It is suggested to adopt experimental thinking , Pay attention to the level of current load , It leads to the change of flow rate and flow time , So as to find a proper balance . Pursuing high resource saturation is not good for product development . 100% resource utilization has the same problem for both manufacturing and software delivery , Will have a great negative impact on the flow rate and flow time .
How to effectively RIH the flowing load to find specific problems ?
It can be reported through stagnant work , Show what unfinished work is in the delivery pipeline , And how long they have stagnated in the current stage .

chart 10: Stagnant work report
By viewing the number of days specified in the system ( Such as 10 God ) Work without progress , You can find problems and bottlenecks in the system , On the one hand, find and eliminate low value “ Zombies need ”, Reduce the amount of work on hold ; On the other hand, identify the blocked work , Through the current stage and the collaborative optimization of upstream and downstream , Promote their resumption of flow as soon as possible . About the common bottlenecks in the R & D process , I will discuss it in the next section .
4. Flow efficiency

chart 11: Flow efficiency
Index definition :
The proportion of the time when the current item is in the active working state in the total time consumed .
How to use :
Measure flow efficiency , It can help the team visualize the waiting time from the bottleneck , In order to find out the problem that leads to the stagnation of flow . The lower the flow efficiency , The longer the work stays waiting . This indicator can be used in combination with other liquidity indicators , Focus on reducing waiting time .
Interpretation of indicators
Higher value :
The higher the flow efficiency , Generally speaking, it indicates that the intersection , It covers the waiting time of upstream and downstream development . If the development team is waiting for user interface design , The designers were assigned to other jobs , Then the flow efficiency will decrease , Because the relevant requirements are waiting , The reason is that neither team has dealt with them . therefore , The bottleneck of value flow can be identified by tracking the reasons for the reduction of flow efficiency . The smoother the payment process 、 The less blocking . But we should also be alert to the situation of too high indicators ( For example, over 40%), This may mean that the state mapping is incorrect or inaccurate , For example, the phase that is actually waiting is mapped into an active state , This will lead to the false high of this index .
The value is low :
It generally indicates that there is a bottleneck 、 Inefficient processes 、 Too many dependencies 、 Lack of resources, etc , These problems will lead to an increase in the current load , Longer queues , And longer flow time .
common problem
Flow efficiency is calculated based on flow time or cycle time ?
Flow efficiency is based on flow time rather than cycle time. Flow efficiency is based on flow time rather than cycle time , It covers the waiting time of upstream and downstream development . If the development team is waiting for user interface design , The designers were assigned to other jobs , Then the flow efficiency will decrease , Because the relevant requirements are waiting , The reason is that neither team has dealt with them . therefore , The bottleneck of value flow can be identified by tracking the reasons for the reduction of flow efficiency .
The normal value of flow efficiency should be appropriate ?
I often see some statistical data in the industry , The actual flow efficiency of many enterprises is much lower than expected , Some adopt the traditional R & D mode 、 Large scale 、 Teams with complex processes , The flow efficiency is not even 10%. When accurate statistics can be made ( The index is not falsely high ), For many businesses , If the flow efficiency reaches 30-40%, It is already a good level .
5. Flow distribution

chart 12: Flow distribution
Index definition :
By showing the flow items completed in a given time ( characteristic 、 defects 、 Risks and liabilities ) The proportion of , To measure the actual investment in different value creation categories .
How to use :
Use flow distribution to bring visibility to different types of work in the value stream , In this way, we can see the focus of current investment from the perspective of priority . If the statistical flow distribution ( Equivalent to the allocation of resources ) Inconsistent with business priorities , You need to adjust . Flow distribution makes the allocation of resources visible , Promote the production research team and the business demander to weigh various work priorities , The trade-off here is a zero sum game . in addition , Flow distribution over time , According to the stage of the product , It needs continuous adjustment and evolution .
Interpretation of indicators
Defects account for a high proportion :
It generally indicates that defects and unplanned work reduce the ability to deliver requirements , Investment in technology debt may need to be strengthened .
Lack of technical debt and risk :
Relevant work is neglected or delayed , Although there seems to be more demand for delivery in the short term , But there may be a debt crisis in the future .
common problem
How to set the flow distribution of each value stream ?
The flow distribution will change over time , Constantly evolving . The value stream of new products is usually adjusted to maximize the proportion of demand delivery . Once the product is launched and has stable users , It is necessary to build additional capabilities to handle possible support work orders and failures , And there is still some work to be done to reduce the accumulated technical debt in the subsequent release cycle .
The above respectively introduces the definitions and interpretation methods of the five liquidity indicators , I believe you have some feelings about how to use them . But one more thing to note is , These indicators remain at the level of software delivery , We should also map R & D work to business results . Associate R & D performance metrics with business results , Real data can be used to determine correlation , And constantly learn and adjust .
Common business outcome indicators include value ( Such as income 、 Annual contract value 、 Number of active users )、 cost ( Such as labor costs 、 Operation and infrastructure costs )、 Satisfaction degree ( Such as net recommended value 、 Employee net recommendation ) etc. , Considering the limited space , Methods and cases on how to map the five flow indicators to business indicators , This article will not be expanded , I'll introduce you later .
3 Common bottlenecks and solutions in the R & D process
Through the five flow indicators , We can effectively measure and analyze the software delivery process , And see through the potential problems and bottlenecks . below , Let's briefly discuss the common bottlenecks in the R & D process and their solutions .
1. Scarce experts or resources , Cause the flow to be blocked

chart 13: The bottleneck causes the flow to be blocked
The phenomenon :
Some active state stage ( Such as “ Development ”) There are bottlenecks , The waiting state stage before this ( Such as “ To be developed ”), There is a lot of stacking work ( High WIP 、 Cycle is long ).
Solutions :
In the active phase with bottlenecks , Increase skilled resources ( But temporary addition may lead to additional burden , Instead, it reduces productivity ); Train team members in professional skills , Or cross professional horizontal training ; Through automation 、 Self service 、 Process optimization or specification simplification .
2. Lack of automation or backward engineering ability , It leads to inefficiency

chart 13: Inefficiency due to lack of Automation
The phenomenon :
Manual processes or interactions that are mainly done manually , Become the bottleneck of flow ; For example, the code needs to be tested in the pre delivery environment , But testing resources are scarce , And the resource application is not self-service , There is a lot of demand piled up in " Waiting for the test " Stage .
Solutions :
Automate the process , Introduce self-service mechanism , Enhance engineering capability ; Improve throughput through automation , Do not rely on resources or expert readiness , So as to improve efficiency ; Do not rely on a centralized team to complete the work according to priority , Such as issuing approval 、 Environmental application, etc .
3. A tedious process , Lead to waiting and long time consuming

chart 14: Cumbersome process leads to waiting
The phenomenon :
Change Approval Committee ( Such as holding an approval meeting every two weeks , No matter how fast the front delivery is, we have to wait )、 Safety approval 、 Fund approval, etc ; Work is waiting , Such as “ Waiting for approval ”, There are many products in these States , Reach the high water mark in the selected time range , Then it decreases periodically .
Solutions :
With high water mark ( Maximum number of products ) For clues , Find the bottleneck problem , Even if the current value has fallen . Automate the change approval process , Criteria for identifying high-risk changes , What must be approved , What are low-risk changes that can be verified automatically 、 Direct deployment .
4. Too much dependence , Cause work flow to stop

chart 15: Too much dependence leads to stagnation of flow
The phenomenon : Wait for something or someone to finish , To keep working .
Architecture dependency ( Software or hardware ): The change of one part causes the function of another part to be destroyed ( for example DB The function call of the other party cannot work due to the change )
Professional knowledge or expert dependence : Experts who need specific expertise ( Such as business experts 、 Security experts ) The input of , Can continue to complete the set work
Activity dependency or event dependency : You need to wait for other activities to complete , Otherwise, the process cannot proceed . For example, the dependencies between several predecessors in the Gantt chart
Solutions :

chart 16: Three kinds of dependence and their solutions
Modeling dependencies ( Such as using dependency matrix ), Communicate with the relying party , Explore solutions ; Long term plan : Take time to remove dependencies , Not just managing them . At the architecture level : Find the fracture surface of the system , Decouple the architecture ; Organizational level : Build a cross functional team , Conduct organizational decoupling . Activity level : Improve self-service and autonomy , Decouple activities .
The last thing to say is this , For the bottleneck in the R & D process , We should think systematically , Take the flow index as the traction to observe the whole value stream , Think about constraints in a holistic way . After finding the bottleneck and clarifying the solution , When implementing improvements , Pay attention to solving only one problem at a time , But not greedy 、 The pursuit of large and complete , In this way, we can independently observe the effect and impact of each measure .

chart 17: Based on data-driven and experimental thinking , One problem at a time
4 summary
The core points of this paper are as follows :
Digital age , Software development itself should also be digitalized .
R & D digitalization , We can start from building an effective R & D efficiency insight system .
Based on lean thinking , Liquidity indicators measure the flow of value , It indicates the efficiency and health of an organization in the process of delivering value .
There are five liquidity indicators : Flow rate 、 Flow time 、 Flowing load 、 Flow efficiency and flow distribution .
Make comprehensive use of these five indicators , We can tell a complete story about the value stream of software development , Answer the essential question about the efficiency of R & D delivery .
Common bottlenecks in the R & D process include scarce experts or resources 、 Lack of automation or backward engineering ability 、 A tedious process 、 Too much dependence, etc , These bottlenecks will lead to blocked flow 、 Let the work stagnate , Lead to waiting and long time consuming .
For the bottleneck in the R & D process , We should think systematically , Take the flow index as the traction to observe the whole value stream , Think about constraints in a holistic way .
When implementing improvements , One problem at a time , In this way, the effect and impact of each measure can be observed independently .
5 The authors introduce
Zhang Le
Tencent Technology Engineering Group DevOps And senior technical experts in R & D effectiveness , Former Baidu engineering efficiency expert 、 Former Jingdong DevOps Platform product director and chief architect , Once worked as Accenture 、 HP and other global top 500 enterprise consultants 、 Senior technical expert . Long term work in a front-line Internet company with tens of thousands of R & D personnel , Focus on R & D efficiency improvement 、 Agility and DevOps Practice landing 、DevOps Tool platform design 、 R & D effectiveness measurement system construction and other directions , yes DevOpsDays The core organizer of the international conference in China , There are many in China DevOps、 Engineering productivity 、 Co chair of the technical conference in the field of R & D effectiveness 、DevOps/ Special producer of R & D Efficiency , yes 《 R & D effectiveness declaration 》 Initiator and drafter of main contents ,EXIN DevOps A full range of internationally certified authorized lecturers 、 Authorized coach of Phoenix Project sand table . Work :《 Practice of improving software R & D efficiency 》、 Translated works :《 Unicorn project : Development legend in the era of digital transformation 》
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